Greenhouse Gas and Carbon Profile of the US Forest Products Industry: 1990 to 2020

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Miner, Barry Malmberg, Adam Costanza, Steve Prisley This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8290322/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 17 You are reading this latest preprint version Abstract This study presents detailed greenhouse gas (GHG) emissions and carbon profiles of the US forest products industry value chain in 1990, 2005 and 2020. Gross emissions were 291, 268 and 172 million metric tons CO2e in 1990, 2005 and 2020, respectively. Between 1990 and 2020, GHG emissions from fuel consumption were reduced by 44%, attributable primarily to fuel switching. Over this period, the greening of the grid resulted in a 43% reduction in emissions attributable to purchased electricity while increased recycling and improved landfill gas control reduced product end-of-life emissions by 61%. These three sources accounted for 64% of gross value chain emissions in 2020 and 93% of the reductions from 1990 to 2020. Forest carbon stocks were stable or increasing on land supplying wood to the industry while stocks of carbon stored in forest products increased by 124 and 97 million metric tons CO2e per year in 1990 and 2020, respectively. Continued progress in reducing value chain emissions will require maintaining stable carbon stocks on wood-supplying land, continued reductions in GHGs associated with purchased fuels and electricity and continued progress in keeping used forest products out of landfills and capturing landfill methane. Earth and environmental sciences/Climate sciences Earth and environmental sciences/Environmental sciences Earth and environmental sciences/Environmental social sciences Forest Products Forest Carbon Carbon Footprint Wood Products Pulp and Paper Life Cycle Assessment Figures Figure 1 INTRODUCTION Fifteen years ago, the National Council for Air and Stream Improvement, Inc. (NCASI) collaborated with the US Forest Service to develop a profile of US forest products industry greenhouse gas (GHG) emissions and sinks in 1990 and 2005 1 . Much has changed since the publication of that study. Energy sources used to power industry and produce electricity have become less GHG-intensive. The production of many forest products has decreased while recovery rates of used products have increased, and many other changes have occurred. In addition, methods used to estimate emissions have evolved. In this study, the profile published in 2010 is updated by adding data for 2020. In addition, earlier estimates are improved by applying the most appropriate data and methods available today. This analysis, like that published in 2010, is based on annual inventory accounting which includes all emissions from the value chain occurring in the year of the inventory, regardless of when the product responsible for the emissions was produced. This contrasts with life cycle assessment accounting which normally includes all emissions from the value change attributed to a single year’s production, regardless of when the emissions occur. An attempt has been made to include all relevant emission categories addressed in the GHG Protocol Corporate Standard, which covers Scope 1 and 2 emissions 2 and the GHG Protocol Value Chain (Scope 3) Standard 3 . For the purposes of this report, Scope 1 emissions are those from manufacturing and converting operations in the forest products value chain. Scope 2 emissions are those released by producers of electricity and steam purchased by the forest products industry. Scope 3 emissions are all other emissions in the forest products industry value chain. In addition, we characterize the net exchange of biogenic carbon between the atmosphere and the US forest products value chain. For a complete description of the emissions Scope concept, see the GHG Protocol Corporate Standard 2 and Supplementary Information. RESULTS Biogenic Carbon Biogenic carbon resides in three pools in the forest products industry value chain: the forest, products in use, and products in landfills. If the total amount of biogenic carbon in these three pools is growing, it means that there has been a net transfer of carbon from the atmosphere into the stocks of carbon stored in these pools (i.e., net carbon removals). Conversely, if the total carbon stocks in these pools is declining, it means that there are net transfers of carbon from the value chain to the atmosphere (i.e., net carbon emissions). While the trends in carbon stocks in the individual pools provide important information, it is only by summing the changes across all three pools that one can calculate the net exchange of biogenic carbon between the atmosphere and the forest products industry value chain. Forest Ecosystem Carbon For the previous GHG and carbon profile in Heath et. al. 1 , the US Forest Service examined the question of industry impacts on forest ecosystem carbon at a level of detail not possible with publicly available data. This previous analysis found that: “Because the complexity of wood flows precludes a precise estimate of forest carbon impacts attributable to the industry, and because carbon stocks on industry-owned lands appear relatively stable, we assume that forest industry landowners manage their forests so that growth and removals are equal over time, resulting in an average net forest carbon change of zero 1 . Since the Heath et. al. study, domestic harvesting first declined then rebounded so that by 2020, it was nearly at the same level as 2005 but still below 1990 levels 4 suggesting that the conclusion from Heath et. al. remains appropriate. Additional insights into the impact of harvesting on forest carbon stocks can be found in data from Oswalt et al. 5 , shown in Chart 1. In 2016, stocks in seven of the eight regions reported by the Resources Planning Act Assessment were increasing, with losses in the Intermountain region due to high levels of mortality from fire and insect damage. The regions with the highest increases in forest stock were the areas with highest harvest levels, as shown in Chart 1. Chart 1 . Net Forest Stock Change in Timberlands and Harvests for Eight US Regions 5 The harvesting and forest data available since 2005, therefore, provide no reason to suspect that carbon stocks are declining on the land that produces wood for the forest products industry. Indeed, all indications are that these stocks are increasing, resulting in net removals of CO 2 from the atmosphere. Furthermore, research continues to show that the demand for wood “reduce[s] transitions of forests to all other rural land uses as well as to developed land uses 6 .” As a result, for purposes of this study, as in Heath et al. 1 , it is concluded that net emissions of biogenic carbon attributable to the forest products industry’s activities in the forest can be conservatively assumed to be zero for the period covered by the analysis. Carbon in Forest Products Estimates of annual changes in carbon held in forest products in-use and in-landfills, published by EPA 4 , are shown Table 1. The amount of carbon leaving the pool of products in use is relatively constant compared to the year-to-year change in inputs to this pool (i.e., new production). As a result, changes in industry production have a large impact on the annual changes in carbon stocks in use. Indeed, during sharp downturns in industry production, such as in 2008, total stocks of carbon in products in use can decline. Net reductions in stocks of carbon in products in use are relatively rare, however, especially for wood products because they remain in use for much longer periods than paper products. The stocks of carbon in the products-in-use pool grew by 14.9 million metric tons C in 1990, 11.6 million metric tons C in 2005, and 8.8 million metric tons C in 2020. The primary reason for the decline in annual growth between 1990 and 2005 was decreasing domestic production of forest products. The annual variability in changes in carbon stocks in landfills is much smaller than changes in stocks of carbon in products in use. This is primarily because inputs to landfill carbon stocks are far less variable than inputs to the pool of products in use. Net additions to landfill carbon stocks in 1990, 2005, and 2020 were 18.8, 17.3, and 17.6 million metric tons C per year, respectively. Table 1. Net Additions to US Product Carbon Stocks in 1990, 2005, and 2020 4 Net C Additions, Million Metric Tons C/yr 1990 2005 2020 In Use 14.9 11.6 8.8 In Landfills 18.8 17.3 17.6 Total 33.8 28.9 26.4 Direct (Scope 1) Emissions from Fuel Combustion The fuel-related direct emissions in 1990, 2005, and 2020 are shown in Table 2. Table 2 . Direct Fuel Combustion-Related Emissions from the Forest Product Industry Million Metric Tons CO 2 e 1990 2005 2020 Pulp and Paper 66.9 55.2 33 Wood Products 3.6 6 4.8 Converting 7.5 13.2 5.9 Total 78 74.4 43.6 Between 1990 and 2020, direct GHG emissions for the US paper, paperboard, and market pulp sector declined from 66.9 to 33.0 million metric tons CO 2 e, a reduction of 51%. Even over the shorter period of 2005 to 2020, emissions were reduced by 40%. Direct GHG emission intensity for the US pulp and paper sector (i.e., tons of emissions per ton of production) was reduced by 48% between 1990 and 2020, from 0.83 metric tons CO 2 e per metric ton production in 1990 to 0.43 in 2020. Changes in direct fuel combustion-related emissions from wood products mills and converting operations are related primarily to changes in production. Approximately three-quarters of the 2020 direct emissions from fuel combustion are associated with the pulp, paper, and paperboard primary manufacturing sector. The industry’s fuel combustion–related emissions in 2020 were reduced by 44% since 1990 and 41% since 2005. Biogenic carbon dioxide emissions have ranged between 135.7 and 144.7 million metric tons per year over the last 30 years. These are not counted in GHG emissions totals, however, because they are included in the mass balance stock change calculations performed on biogenic carbon, described above and in detail in Supplementary Information. Emissions from Producers of Purchased Electricity (Scope 2) Indirect emissions associated with purchases of electricity and steam (Scope 2, under the GHG protocol 2 ) are shown in Table 3. Emissions reductions from 1990 to 2020 were approximately 50% for both gross- and net- electricity–based estimates. The same is true for the period of 2005 to 2020. Emissions associated with net energy purchases (including steam) were 20.0%, 16.6%, and 17.7% lower than those based on gross purchases (including steam) in 1990, 2005, and 2020, respectively. Emissions attributable to purchased steam account for about 9% (range from 5 to 13%) of emissions from gross purchases of steam and electricity. Table 3 . Indirect Scope 2 Emissions Attributable to Electricity and Steam Purchases in the US Paper, Paperboard, and Market Pulp Sector Million Metric Tons CO 2 e 1990 2005 2020 Pulp and Paper Based on Gross Purchases 32.3 33.0 16.5 Based on Net Purchases 24.1 24.4 11.7 Wood Products Based on Gross Purchases 12.6 16.2 9.2 Based on Net Purchases 11.8 15.8 8.9 Converting Based on Gross Purchases 19.1 19.7 10.7 Based on Net Purchases 19.1 19.7 10.7 Total Forest Products Industry Based on Gross Purchases 64.0 68.9 36.4 Based on Net Purchases 55.0 59.9 31.3 Emissions intensity based on gross purchased electricity (not including steam) declined from 0.38 to 0.19 tons CO 2 per ton production from 1990 to 2020 while intensity based on net purchased electricity declined from 0.30 to 0.15 tons CO 2 per ton production. Much of the reduction in emissions associated with purchased electricity have been attributable to the greening of the grid. Since 2005, there has been a 38% reduction in the national average purchased electricity GHG emission factor 7 . For wood product mills, Scope 2 associated with gross purchased electricity in 2020 were 43% lower than in 2005 and 27% lower than in 1990. Reductions in emissions associated with net electricity are similar. On average, 93% (ranging from 91 to 95%) of the converting emissions associated with purchased electricity are in the pulp and paperboard sector. In 2020, the pulp, paper, and paperboard sector accounted for 45% of all Scope 2 emissions. Wood products accounted for 25%. The converting sector accounted for 30%, almost all of which was associated with converting paper and paperboard. Between 1990 and 2020, these emissions were reduced by 47%. Scope 3 Emissions Associated with Purchased Fossil Fuels and Electricity Indirect emissions associated with the production and transport of fossil fuels used by the US forest products Industry and by its suppliers of purchased electricity and steam are considered Scope 3 emissions under the GHG Protocol 2 , 3 . Emissions associated with production and transport of fuels used by the industry are calculated to have been 11.1, 11.1, and 7.9 million metric tons CO 2 e in 1990, 2005, and 2020 respectively. Corresponding emissions associated with fuels used by suppliers of electricity to the industry were 3.7, 4.7 and 4.0 million metric tons CO 2 e in 1990, 2005 and 2020, respectively. Emissions Associated with Producing and Harvesting Wood GHG emissions are released in the production and harvesting of roundwood, for instance from equipment used for planting and harvesting. Chemicals may be used for weed and pest control and fertilization, and fire may also be used as a management tool. These emissions, which are considered to be Scope 1 for purposes of this report, are estimated to have been only 2.5, 2.3, and 2.1 million metric tons CO 2 e in 1990, 2005 and 2020, respectively. The reductions in emissions reflect reductions in domestic roundwood production. Note that these do not include transport-related emissions, which are addressed elsewhere in this report. The estimate developed for this report is significantly higher than US EPA’s estimate of emissions associated with nitrogen fertilizer use in forestry 8 because EPA’s estimates do not include Scope 3 emissions associated with producing forest chemicals and fossil fuels used in forestry (which are included in this report’s estimates although they are classified as Scope 1). Upstream Scope 3 Emissions Associated with Non-Fiber, Non-Fuel Inputs Emissions attributable to producing non-fiber, non-fuel inputs to manufacturing (e.g., additives, process chemicals) have declined over time primarily due to an overall reduction in production of paper and paperboard. The emissions associated with the paper and paperboard sector were 7.4, 8.4 and 6.2 million metric tons CO 2 e in 1009, 2005 and 2020, respectively. Those in the wood products sector were 5.4, 6.5 and 5.2 million metric tons CO 2 e in 1990, 2005 and 2020, respectively. These reductions in the paper and paperboard sector were especially large between 2005 and 2020 due to a 70% reduction in production of newsprint and printing/writing grades 9 , grades associated with higher upstream non-fiber, nonfuel emissions. This has caused the overall production-weighted average factor for the paper, paperboard, and market pulp sector to decline, being 94.6, 92.8, and 83.4 kg CO 2 per metric ton production in 1990, 2005, and 2020, respectively. Emissions From Systems Managing Forest Products Industry Wastes Pulp and paper mills as well as wood products mills can produce boiler ash and a variety of miscellaneous solid wastes. In addition, pulp and paper mills often generate wastewater treatment residuals and recovery area wastes. Sizable fractions of these solid wastes are landfilled, producing methane over time. The landfill emissions associated with landfilled solid wastes from the industry were 312, 394 and 386 thousand metric tons methane in 1990, 2005 and 2020, respectively. Using a global warming potential for methane of 25, these equate to emissions of 7.8, 9.9 and 9.7 million metric tons CO 2 e in 1990, 2005 and 2020, respectively. Over 90% of the industry’s landfill methane emissions are attributable to pulp and paper mill wastes, and 50% to 60% of pulp and paper mill landfill emissions are attributable to wastewater treatment plant residuals. Small amounts of methane and nitrous oxide emissions are also associated with the treatment of wastewater from pulp and paper mills. These totaled 1.6, 1.4 and 0.9 million metric tons CO 2 e in 1990, 2005 and 2020, respectively. Transport Emissions in the Forest Products Industry Value Chain Transport emissions along the forest products industry value chain are shown in Table 4, Transport-related emissions in 2020 were 10% lower than in 1990 and 18% lower than in 2005. The changes over time reflect primarily (a) changes in the ton-km values reported in the Commodity Flow Survey 10 and (b) improvements in transport fuel efficiency. Approximately 73% of these emissions are associated with transport of products. The results reflect multiple sequential shipments of the same fiber as it is transformed from raw material leaving the forest into final products at the retail level. Emissions associated with transport of roundwood are also large because, even though the transport distances are relatively small, logs contain a significant amount of water and the vehicles return to the forest empty, doubling the one-way haul distance attributed to each load. Table 4. Emissions Attributable to Transport in the US Forest Products Industry Value Chain Million Metric Tons CO 2 e 1990 2005 2020 Raw Materials All roundwood, including firewood 4.37 4.02 3.36 Recovered fiber (shown as used products below) See used products Paper and paperboard non-fiber, non-fuel inputs 0.17 0.18 0.12 Wood product non-fiber, non-fuel inputs 0.01 0.02 0.01 Products Wood products 7.37 7.52 6.01 Paper and paperboard 5.20 5.94 5.47 Paper articles 1.49 2.31 1.91 Printed materials 1.58 1.84 0.83 Wood-based pellets 0 0.06 0.40 Used Products Used Products 1.57 1.84 1.44 Total 21.8 23.7 19.5 Fraction of 1990 total emissions 1.00 1.09 0.90 Fraction of 2005 total emissions 1.00 0.82 Emissions Resulting from Use of Forest Products Emissions attributable to the use of forest products are limited to those from the use of wood-based fuels. Emissions from the industrial use of wood-based fuels are almost entirely from the forest products industry and are included in Table 2 above. The nonindustrial GHG emissions associated with the use of wood-derived fuels produced in the US were 9.1, 5.5 and 5.9 million metric tons CO 2 e in 1990, 2005 and 2020, respectively. These emissions are dominated by methane emissions from residential use of wood for energy. Residential firewood accounted for 84% of nonindustrial wood energy emissions in 2017 but decreased through the 1990s due to a decline in residential use of wood for fuel. Attributing all firewood emissions to the forest products industry value chain implies that everyone cutting and selling firewood is part of that value chain. The appropriateness of this approach could be questioned, especially in areas where firewood is collected by individuals for their own use. Emissions from Forest Product End-of-Life The landfilling of used forest products at end-of-life results in methane emissions. Methane emissions attributable to landfilled forest products amounted to 78.6, 51.0 and 30.5 million metric tons CO 2 e in 1990, 2005 and 2020, respectively. Approximately 90% to 95% of these emissions are attributable to paper and paper products. Except for methane emissions from MSW landfills, end-of-life emissions are expected to be small, as discussed in Supplementary Information. Summary of Forest Product Industry Value Chain GHG Emissions The emissions from the forest product industry value chain for 1990, 2005 and 2020 are summarized in Table 5. The results are presented both in terms of gross and net emissions. Because stocks of biogenic carbon in the value chain are increasing, there is a net transfer of CO 2 from the atmosphere into the value chain which can be expressed as a negative emission of CO 2 . This net removal of CO 2 from the atmosphere is considered in calculating net GHG emissions but not gross GHG emissions. Table 5. Gross and Net Emissions Attributable to the Forest Products Industry Value Emission Category Million Metric Tons CO 2 e % of 2020 Gross Emissions 1990 2005 2020 Biogenic CO 2 Accounting Changes in forest ecosystem carbon stocks 0* 0* 0* Not Applicable Changes in product carbon stocks 123.8 106.0 96.8 Not Applicable Net Emissions of Biogenic CO 2 −123.8** −106.0** −96.8** Not Applicable GHGs Other Than Biogenic CO 2 Scope 1 fuel combustion 78.0 74.4 43.6 25% Scope 2 (based on gross energy purchases) 64.0 68.8 36.4 21% Management of Mill Wastes 9.4 11.2 10.6 6% Transport 21.8 23.7 19.5 11% Upstream – Purchased electricity 3.7 4.7 4.0 2% Upstream – Non-fiber input production 12.8 14.9 11.5 7% Upstream – Fossil fuel production and transport 11.1 11.1 7.9 5% Product use (84 to 96% residential wood fuel emissions) 9.1 5.5 5.9 3% Wood supply production 2.5 2.3 2.1 1% Product end-of-life 78.6 51.0 30.5 18% Gross value chain emissions*** 291.1 267.7 172.2 100% Net value chain emissions 167.2 161.7 75.4 * Based on a conservative analysis of forest carbon stocks as described in Section 2 of this paper. ** Negative values indicate a net removal of CO 2 from the atmosphere. *** Excluding net biogenic CO 2 emissions DISCUSSION Scope 1 emissions from industry fuel combustion and Scope 2 emissions for manufacturing and converting operations accounted for 46.5% of the industry’s gross value chain emissions (i.e., not considering net removals of CO 2 from the atmosphere attributable to growth in stocks of biogenic carbon). An additional 18% were attributable to methane releases from landfilled forest products. The only other aspect of the value chain contributing more than 10% of total value chain emissions was transport, accounting for 11%. Changes in GHG emissions and industry production are shown in Table 6. Between 1990 and 2020, gross emissions declined by 41% while production declined by less than 10%. During the period of 2005 to 2020, gross emissions declined by 36% while production decreased by 21%. Like gross emissions, net emissions (which include the effects of changes in stocks of forest carbon) have declined over time, with net emissions in 2020 being 55% below 1990 and 53% below 2005 net emissions. The calculations of net emissions of forest carbon rely on the observation, consistent with available data, that forest carbon stocks on land used to produce wood for the industry are stable or increasing. This justifies a conservative assumption of zero net change in forest carbon stocks in the calculations. The primary reason for the decline in annual additions to stocks of carbon in products in use between 1990 and 2005 was decreasing domestic harvest. Between 1990 and 2006 the decline in domestic wood production was gradual, but the 2007–2009 recession caused a dramatic downturn in harvesting of wood, which had the expected impact on changes in stocks of carbon in products in use. Wood production and in-use carbon stocks subsequently increased. A large fraction of the growth in carbon stocks in products in use is attributable to wood products (See Supplementary Information). The factors contributing most to overall reductions in gross value chain emissions are examined in Table 7. Reductions in emissions associated with fuel combustion, purchased electricity and landfilling of used products at end-of-life accounted for 93% of the reductions between 1990 and 2020 and 88% of the reductions between 2005 and 2020. The reductions in fuel combustion-related emissions have been due primarily to increased use of biomass fuel, reduced use of coal and changes in production. In 1991, coal and other fossil fuels (primarily residual fuel oil) represented 13% and 7% of the on-site energy mix, respectively. By 2018, the coal contribution had decreased to 3%, and the contribution other fossil fuels had dropped to 1%. Between 1991 and 2018, the natural gas energy contribution increased from 20% to 26%, and the biomass energy contribution increased from 53% to 63%. These changes contributed to GHG reductions on both intensity and absolute bases for the US pulp and paper industry. Additional discussion of these emissions and the factors affecting them can be found in Supplementary Information. Table 6. Emissions and Production in 2020 Relative to Emissions in 1990 and 2005 Emission Category Fraction of 1990 Fraction of 2005 Scope 1 fuel combustion 0.56 0.59 Scope 2 (based on gross energy purchases) 0.57 0.53 Management of Mill Wastes 1.12 0.94 Transport 0.90 0.82 Upstream – Purchased electricity 1.08 0.86 Upstream – Non-fiber input production 0.89 0.77 Upstream – Fossil fuel production and transport 0.71 0.72 Product use (84 to 96% residential wood fuel emissions) 0.65 1.08 Wood supply production 0.84 0.92 Product end-of-life 0.39 0.60 Total Gross Emissions 0.59 0.64 Paper and Paperboard Production 0.92 0.79 Wood Products Production 0.91 0.79 The contribution of forest products to municipal solid waste (MSW) landfill methane releases has decreased over time. The primary reason is that paper and paperboard’s contribution to MSW has diminished. In 1990, paper and paperboard represented 30% of MSW landfill input. By 2018, this had dropped to 11.8%. In addition, the use of methane capture systems at MSW landfills has increased. Table 7 . Contribution Analysis of Reductions in Gross GHG Emissions from the Forest Products Industry Value Chain Category Percentage of 1990 to 2020 Change Percentage of 2005 to 2020 Change Scope 1 Fuel Combustion 29% 32% Scope 2 23% 34% Management of Mill Wastes -1% 1% Transport 2% 4% Upstream - Purchased Electricity 0% 1% Upstream - Non-fiber input production 1% 4% Upstream - Fossil fuel production and transport 3% 3% Product Use (84 to 96% residential wood fuel emissions) 3% 0% Wood Supply Production 0% 0% Product End-of-Life 40% 21% Total Gross Emissions 100% 100% METHODS Greenhouse gas emission factors Fuel-specific emission factors 11 and GWPs 12 published by the Intergovernmental Panel on Climate Change (IPCC) were used to convert subsector fuel use data into Scope 1 GHG emissions. However, in calculating CO 2 e emissions for CH 4 and N 2 O from biomass combustion, factors from GHG Protocol Calculation Tools 13 were used because of their better representation of CH 4 and N 2 O emissions from US pulp and paper facilities. GHG emission factors for purchased electricity are taken from EPA’s Emissions & Generation Resource Integrated Database (eGRID) and are based on national averages for a given reporting year 7 . Additional information on the sources and application of GHG emission factors is contained in Supplementary Information. Biogenic Carbon Forest Ecosystem Carbon The US Forest Service develops periodic estimates of carbon stocks and fluxes in forest ecosystems. The US Environmental Protection Agency (US EPA) publishes these in its annual report on GHG emissions and sinks. Data for 1990 to 2020 were sourced from US EPA’s Inventory of Greenhouse Gases and Sinks: 1990–2022 and the annexes to that inventory (US EPA 2024a; US EPA 2024b). The estimated net growth in carbon stocks in US forests in 2020 (208.6 million metric tons per year) is equivalent to removing 765 million metric tons CO 2 from the atmosphere annually (converting carbon to CO 2 equivalents (CO 2 eq.) by multiplying by 44/12). Although land use is not considered in the calculations for this report, these effects are small. Since 1990, the gains and losses of forest land in the US have resulted in a net loss of 5 to 7 million metric tons of forest ecosystem carbon per year (calculated from data in US EPA 2022a). It must be noted that the data on forest ecosystem carbon stocks include forests that are not used to produce industrial roundwood. Therefore, additional analyses, described in the results above, were performed. The additional analysis found no evidence that carbon stocks are declining on wood-producing land. Carbon Stored in Forest Products The changes in product carbon stocks are published by EPA in its annual inventory 4 . The stock change values for 1990 and 2005 in this update differ from those reported in Heath et all. 2010 1 . The primary reason is that, in recent inventories, US EPA updated its past estimates based on updated analysis by the US Forest Service. US EPA lowered the 1990 increase in stocks of in-use carbon to 14.9 from 17.7 million metric tons C. Likewise, the estimated increase for 2005 has been reduced to 11.6 from 12.1 in earlier US EPA inventory reports. The data and calculations for carbon in products in use and in landfills are described in Supplementary Information. Direct (Scope 1) Emissions from Fossil Fuel Combustion Pulp and Paper Sector Data Sources Available government and industry data sets were synthesized for GHG emission calculations. The primary sources were: US Energy Information Administration Manufacturing Energy Consumption Survey (MECS) 14 American Forest and Paper Association/American Paper Institute 9 . Because these data are collected annually and agree closely with the less frequently collected MECS data, the AF&PA data are used as the primary source of pulp and paper sector data in this analysis. US EPA Greenhouse Gas Reporting Program (GHGRP) 15 . Because the GHGRP only began in 2010, it was primarily used for comparison to other data sources. The use of these data sources and how they compare are discussed in detail in Supplemental Information. Wood Products Data Sources Combustion-related emissions from wood product facilities were calculated from energy consumption data in MECS reports 14 from 1991 through 2018 and wood products production from FAOSTAT’s Forestry Production and Trade database 16 . These data, and their use in calculating emissions, are discussed in Supplementary Information. Converting Operations Data Sources In most cases, wood and paper products require additional manufacturing to produce final products. There are many so-called converting operations. In the case of paper and paperboard products, these include printing, packaging, cutting, folding and gluing, and many others. In the case of wood products, these include converting wood into furniture, housing, and many other products. Because of the great variety in converting operations, any estimate of emissions associated with this part of the forest products industry value chain is subject to considerable uncertainty. This report contains estimates of emissions from some converting operations not included in the previous profile published by Heath et.al. 1 In addition, methods to estimate process energy-related emissions have been improved compared to the previous profile. As a result, there are differences between the estimates presented herein and those published in Heath et al. Previous estimates have been revised, however, using the updated methods, allowing a consistent comparison of emissions in 1990, 2005, and 2020. For this profile, estimates associated with converting were drawn primarily from EIA MECS data 14 . It is important to note that the EIA MECS data do not include all types of final processing operations performed on forest products. Also, for some EIA MECS sectors, materials other than forest products may be included in an NAICS code. Nonetheless, EIA MECS data provide a consistent series of data over time. The adjustments to, and use of, MECS data to calculate GHG emissions attributable to converting forest products into final products are described in detail in Supplementary Information. In the case of wood products, an additional contribution, not accounted for in MECS data, was calculated for converting wood products into housing. These data and methods used for calculating emissions from housing construction are also described in Supplementary Information. The analysis of converting emissions calculations indicates that these estimates are subject to considerable uncertainty, with estimated changes over time highly sensitive to the years selected for the comparison. Emissions from Producers of Purchased Electricity (Scope 2) Emissions from purchased electricity are calculated by multiplying electricity purchases by the associated GHG emission factor. This study does not include carbon credits (e.g., renewable energy credits or RECS) purchased or sold by the forest products industry. Details on emission factor sources and GWPs used in calculations are provided above. Where possible, emissions estimates were shown in two ways, based on gross electricity purchases and net electricity purchases. Many inventory protocols, including the GHG Protocol, require estimates based on gross purchases 2 . Estimates based on net purchases, however, can be more reflective of the amounts of electricity consumed in manufacturing. Where data allow, estimates are also shown that include purchases of steam. Gross purchases are used as the baseline estimates for this study. The previous GHG profile study 1 used net purchases to calculate Scope 2 emissions. Pulp and Paper Sector Data Sources The same sources of data were used here as in the calculation of fuel combustion-related emissions, with the AF&PA being the primary data source. Additional discussion of the use of these sources and how they compare is provided in Supplementary Information. Wood Product Mills Data Sources Data on electricity purchases by wood products mills were obtained from EIA MECS 14 . These data, and their use in calculating emissions are described in Supplemental Information. Converting Operations Data Sources Scope 2 emissions for converting operations were estimated using the same approach as used for direct fuel combustion-related emissions (described previously). It is assumed that for converting operations, gross and net electricity purchases are equal; therefore, results are shown for gross purchases only. Additional analysis of these emissions is shown in Supplementary Information. Scope 3 Indirect Emissions Associated with the Production and Transport of Fossil Fuels Used by the US Forest Products Industry and by its Suppliers of Electricity GHGs are emitted in the production and transport of fuels used in the forest products industry. Upstream emission factors for the production and transport of fuels used by the industry were obtained from NCASI’s Scope 3 GHG Screening Tool, version 1.1a 17 . These factors indicate that upstream GHG emissions associated with natural gas, oil, and coal are 19.8%, 16.1%, and 6.1% of the combustion emissions, respectively. Using these and EIA MECS data 14 to determine the mix of fuels in 1991, 2006, and 2018, a fuel-weighted ratio of upstream to combustions emissions was developed for each year and sector. The EIA survey years were used to represent 1990, 2008 and 2020 in the calculations for this report. These ratios remain relatively constant over this period for the pulp and paper converting, wood products, and wood products converting sectors at 0.20, 0.19 and 0.19 respectively. However, the factor for the pulp and paper sector went from 0.13 in 1991 and 2006 to 0.18 in 2018. due to an increased reliance on natural gas, for which upstream emissions are higher than for other fossil fuels. Emissions in 1990, 2005, and 2020 associated with producing and transporting fuels used by suppliers of electricity were estimated using data from the National Renewable Energy Laboratory (NREL) on the ongoing upstream GHG emissions attributable to different types of power 18 and information on the composition of the grid, as reported by eGRID 7 . These data, and their application are discussed in Supplementary Information. Although the NREL fact sheet 18 suggests that its factors include transport emissions, the underlying literature source 19 indicates that transport is not included in the factors so the factors were adjusted to include transport. The resulting Scope 3 factors based on the average composition of the grid were determined to be 38, 41 and 41 kg CO 2 e per MWh in 1990, 2005 and 2020 respectively. The details on calculation of these factors are shown in Supplemental Information. Emissions Associated with Producing and Harvesting Wood Factors that address these emissions have been developed for NCASI’s Scope 3 GHG Screening Tool, version 1.1a 17 and have been used in this study. For purposes of this study, these are assumed to be Scope 1 Emissions. Factors are available in the Screening Tool for production and harvesting of hardwood and softwood from the north and south US. The fraction of northern and southern, hardwood and softwood, were calculated from Table 39 in Oswalt et al. 5 . Wood from other regions, which accounts for approximately 20% of US harvest, was ignored in calculating a weighted average factor for the US. The national weighted average factor was determined to be 0.0111 kg CO 2 e per kg dry wood harvested. The weighted factor was assumed to apply equally to current and past wood production and harvesting. Emissions were therefore calculated by multiplying this factor by the quantity of roundwood production in 1990, 2005, and 2020. Roundwood production data were obtained from FAOSTAT 16 . It was assumed that a cubic meter of green wood weighs 0.9 metric tons and all wood is 50% water. Upstream Scope 3 Emissions Associated with Non-Fiber, Non-Fuel Inputs To estimate upstream emissions associated with non-fiber, non-fuel inputs (e.g., additives and process chemicals), NCASI divided the industry into product types. For each product type, upstream emissions associated with non-fiber inputs to manufacturing (not including fuels) were estimated using factors contained in the Forest Industry Carbon Assessment Tool (FICAT) 20 , a model developed by NCASI for the International Finance Corporation of the World Bank. The list of product types and associated FICAT factors are shown in Supplemental Information. Production levels for pulp, paper, and paperboard were obtained from AF&PA statistical reports 9,21 . Data on wood product output was obtained from Howard and Liang 22 . The most recent wood products data available were for 2017; therefore, these were used to represent 2020. Emissions From Systems Managing Forest Products Industry Wastes Pulp and Paper Mill Solid Wastes In this report, methane emissions are calculated for four different wastes that may be disposed of in mill landfills: wastewater treatment residuals (WWTR), boiler ash, recovery area wastes, and other wastes. US EPA’s GHGRP includes calculation parameters for all of these wastes 15 . The GHGRP also includes parameter values for combined wastes from pulp and paper mills, but the estimates here assume the materials are landfilled separately. A comparison of estimates from separate and combined disposal are shown in Supplemental Information. Landfills receiving mill solid wastes are assumed to be lacking engineered methane collection systems. Estimated landfill methane emissions associated with some of these wastes are available from EPA national inventory reports 4 and from the GHGRP 15 . The estimates in this report are based primarily on GHGRP methods and parameter values applied to data from industry sources. A comparison of EPA estimates, GHGRP reported estimates and those derived here is available in Supplemental Information. Wastewater Treatment Residuals (WWTR) For estimating methane emissions attributable to WWTR in landfills, the first order decay model and default parameters in the GHGRP have been used. In specific; a value of 0.12 kg organic C pr kg wet waste has been used for Degradable Organic Carbon (DOC), a value of 0.5 has been used for the fraction of DOC that will degrade in the landfill (DOCf), a value of 0.04 has been used for the first order decay rate (k) which is the default value for moderate climate, a value of 1.0 has been used for the fraction of degradable carbon subjected to anaerobic conditions (MCF), a value of 0.5 has been used to represent the fraction of degraded carbon that is converted to methane (F) and, a value of 0.1 has been used to represent the fraction of generated methane that is oxidized naturally in the upper layers of the landfill before being released to the atmosphere (OX.) The amounts of WWTR generated and landfilled were estimated from NCASI survey data to construct a series of annual values starting in 1960 and ending in 2020 23 . Details are provided in Supplemental Information. Methane releases for each year from 1990 were estimated using the calculation approach in Subpart TT of the GHGRP 15 . In Supplementary Information, the results of these calculations are compared to estimates derived from EPA national inventories 24 and from GHGRP data 15 . Boiler Ash Landfill methane emissions attributable to boiler ash are seldom estimated, being assumed to be small. This assumption is based on the low content of organic matter and, in the case of ash derived from wood and bark (hereafter referred to as simply wood ash), the high pH. The pH of wood ash is seldom below 10 25,26 , while methane production is not favored at such a high pH 27 . Given that companies are required to report ash landfills under the GHGRP, however, methane attributable to ash (wood and coal) disposal is estimated in this profile. Information on the quantities of ash produced by pulp and paper mills has been collected by NCASI since the mid-1990s 23 . The use of these data to develop a time series of ash quantities is described in Supplemental Information. The Subpart TT default parameter values used in the GHGRP to model methane emissions from boiler ash landfills are the same as those for WWTR except (a) a value of 0.06 kg organic C pr kg wet waste is used for Degradable Organic Carbon (DOC), and (b) a value of 0.03 is used for the first order decay rate (k) which is the default value for moderate climate. The DOC values in the GHGRP Subpart TT rules are on a wet weight basis. Generation rates, however, are on a dry weight basis, requiring a factor to convert to as-disposed wet weight. Factors were developed, therefore, for converting from wet basis to dry basis. The development of these factors in described in Supplemental Information. Recovery Area Waste The recovery area of kraft pulp mills can produce several waste streams, often collectively called causticizing area waters. The three main wastes are lime mud, slaker grit, and green liquor dregs. These have not been included in past attempts to estimate methane emissions from mill landfills due to their relatively small quantities, low organic content, and typically elevated pH, which is generally not conducive to methane production. Nonetheless, the GHGRP contains parameter values for estimating landfill methane emissions attributable to these materials 15 . NCASI survey 23 data and published reports allow estimates of the past quantities of recovery waste produced and landfilled 28,29 . The data and calculations are shown in Supplemental Information. The parameter values used to model methane attributable to landfilled recovery area wastes were the same as for WWTR except (a) (a) a value of 0.025 kg organic C pr kg wet waste is used for Degradable Organic Carbon (DOC), and (b) a value of 0.03 is used for the first order decay rate (k) which is the default value for moderate climate. Other Waste from Pulp and Paper Mills The amounts of other waste being landfilled were derived using the same set of data as described for recovery area wastes. Calculations are shown in Supplemental Information. The parameter values used to model methane attributable to landfilled “other waste” were the same as for WWTR except (a) a value of 0.2 kg organic C pr kg wet waste is used for Degradable Organic Carbon (DOC), and (b) a value of 0.03 is used for the first order decay rate (k) which is the default value for moderate climate. Solid Waste from Wood Products Facilities – Lumber Mills Wood products manufacturers often use wood-derived fuels that produce boiler ash. In addition, other wastes can be associated with wood handling and manufacturing operations. For this profile, therefore, methane emissions attributable to landfilling of ash and non-ash wastes were estimated. Non-ash wastes from wood products mills can include wood yard waste and manufacturing waste not suitable for use as fuel, as a raw material in the mill, or elsewhere. The products and processes used at wood product plants vary. The available waste-related data, however, do not allow detailed differentiation between types of mills. Therefore, for this analysis, the wood products industry was divided into only two sectors: lumber and panels. The lumber category includes all softwood and hardwood lumber while the panel category includes all panels and engineered wood products. Boiler Ash There are few survey data available on the amounts and types of solid waste from wood products mills. For this profile, NCASI calculated ash quantities based primarily on data on biomass energy consumption reported in EIA MECS surveys 14 . The data and calculations are shown in Supplemental Information. Disposal methods were assumed to be the same as a pulp and paper mills. The DOC values in GHGRP Subpart TT rules 15 are on a wet weight basis. Generation rates, however, are on a dry basis, requiring a factor to convert them to as-disposed wet weight. The calculations were performed assuming that the average solids content for ash disposal from 1990 to 2020, equal to 83% (see Supplemental Information). The parameter values used for modeling methane emissions attributable to landfilled ash from lumber mills were the same as those used for ash from pulp and paper mills. Other Wastes Studies published by the Consortium for Research on Renewable Industrial Materials (CORRIM) [1] were used to develop a factor for estimating the amounts of non-ash solid waste landfilled at lumber mills. The use of these reports to calculate waste quantities is described in Supplemental Information. The DOC values in GHGRP Subpart TT 15 are on a wet weight basis; therefore, the dry weights estimated herein were converted to wet weights using a solids content of 85% based on the fact that the GHGRP DOC is taken from IPCC 11 , where the associated water content is 15%. The GHGRP Subpart TT defaults for non-ash waste from wood and wood products mills are the same as for “other waste” from pulp and paper mills except a value of 0.43 kg organic C pr kg wet waste is used for Degradable Organic Carbon (DOC). This is more than twice the value for “other” wastes from pulp and paper mills (0.2). The default value for DOCf, however, is 0.5 for other wastes from both pulp and paper mills and lumber mills. In considering these parameter values, it is important to consider that, at lumber mills, this waste is primarily comprised of woody material that is not usable as raw material or fuel. The GHGRP default DOCf of 0.5, however, is not consistent with current research on the ultimate degradability of woody materials in anaerobic landfills 30,31 . US EPA’s Waste Reduction Model (WARM), for instance, considers 88% of the carbon in lumber and 77% of the carbon in branches to be nondegradable in anaerobic landfills 30 . These are equivalent to DOCf values of 0.12 and 0.23, respectively. In this study, therefore, a value of 0.2 has been used for DOCf for other wastes from lumber mills. Additional analysis the value for woody waste DOCf is contained in Supplemental Information. Solid Waste from Wood Products Facilities – Panel Plants Boiler Ash The approach to estimating methane attributable to landfilled boiler ash at panel plants was the same as described earlier for lumber mills. The calculations are shown in Supplemental Information. The fraction of ash landfilled was assumed to be the same as that for lumber mills, described previously. US EPA’s current default DOC values for boiler ash are based on as-disposed solids content. Therefore, for the calculations in this update, DOC was converted to a dry basis using the same assumptions for solids content as used for lumber mills (i.e., 83% solids). The parameter values used for modeling methane emissions attributable to landfilled ash from panel plants were the same as those used for lumber mills. Other Wastes Studies published by the Consortium for Research on Renewable Industrial Materials (CORRIM) [2] were used to develop a factor for estimating the amounts of non-ash solid waste landfilled at panel plants. The use of these reports to calculate waste quantities is described in Supplemental Information. The DOC values in GHGRP Subpart TT are on a wet weight basis; therefore, the dry weights estimated herein were converted to wet weights using a solids content of 85% based on the fact that the Subpart TT DOC is taken from IPCC 11 , in which the associated water content is 15%. The parameters for modeling “other” waste from panel plants were the same as used for lumber mills. Details are provided in Supplementary Information. Pulp and Paper Mill Wastewaters Wood product mills seldom produce wastewater. Most pulp and paper mills, however, do. In its 2022 annual inventory of GHG emissions and sinks, US EPA estimated 2020 GHG emissions from the treatment of pulp, paper, and paperboard mill wastewaters 32 . US EPA’s estimates are model-based and are subject to considerable uncertainty. Nonetheless, US EPA’s estimates are used as the basis for this updated inventory. US EPA estimates wastewater treatment emissions using IPCC models that calculate methane release based on information regarding the amount of organic matter subject to anaerobic conditions and factors that convert a fraction of this material into methane. US EPA also estimates nitrous oxide emissions associated with treating industry wastewater 32 . To develop estimates for this profile, is it assumed that the most important parameter in US EPA’s calculations that changed significantly since 1990 was the amount of organic matter in untreated wastewater. Accordingly, estimates of 1990 and 2005 emissions were produced by scaling US EPA’s 2020 estimate based on influent loads. Data in NCASI 2019 indicate that influent loads decreased from about 25 kg BOD/metric ton production in 1990 to 15 kg/metric ton in 2020. Production data to convert these to mass loads were taken from US EPA 24 . It Is important to note that US EPA’s estimates for N 2 O emissions include emissions from wastewater treatment plants as well as emissions that occur in the environment attributable to the residual nitrogen in industry effluents. Transport-Related Emissions The forest products industry’s value chain requires transport of fibrous and nonfibrous raw materials, products, fuels, and wastes. This section contains calculations for the emissions associated with these transport operations except for the transport of fossil fuels used by manufacturing and converting operations (which is included in the factors used to calculate Scope 3 emissions for fuels earlier in this report). In the context of this report, these emissions are those associated with fossil fuel consumption by transport vehicles and are reported as Scope 3 whether the vehicles are owned by a forest products company or not. The estimates of transport-related emissions developed in this study rely heavily on data from the Census Bureau Commodity Flow Survey (CFS) 10 . Factors to consider when using CFS data are discussed in Supplementary Information. Roundwood Transport Although most of the transport-related calculations in this report are based on information from the CFS 10 , this is not possible for roundwood transport because the CFS does not cover the “forestry and logging” industry (additional information is available in Supplemental Information). Instead, emissions associated with roundwood transport are calculated using the assumptions and values shown in Table 8. Product Transport CFS data 10 are used in this report for estimating transport-related emissions for wood and paper products, both primary products and converted products. The products of interest to the US forest products are assigned SCTG codes 26, 27, 28, and 29. Detailed information on the CFS and its use in this report is available in Supplemental Information. Emissions are calculated by multiplying the metric ton-km values from CFS reports by emission factors derived from multiple sources.The emission factors used for heavy-duty trucks are shown in Table 8. Emission factors for rail were obtained from the US Department of Transportation based on reported fuel efficiencies 332, 414, and 487 short ton-miles per gallon of fuel consumed in 1990, 2005, and 2020, respectively 45 . Using emission factors for diesel fuel (see Table 8), these values can be converted to emission factors of 0.0211, 0.0169, and 0.0144 kg CO 2 per metric ton-km, respectively. Assuming that all transport of products was by truck or rail, these factors for trucking and rail transport were weighted (based on metric ton-km for each mode of transport) 10 to derive an overall emission factor for each commodity. For SCTG codes 26 through 29, the ranges of weighted emission factors were 0.051 to 0.056 kg CO 2 e per metric ton-km in 1990 and 2005 and 0.045 to 0.051 kg CO 2 e per metric ton-km in 2020. SCTG code-specific values are shown in Supplementary Information. Table 8. Assumptions and Values Used to Calculate Roundwood Transport Emissions Variable Value Sources Roundwood transported (includes firewood) 1990, 445 million metric tons 2005, 408 million metric tons 2020, 376 million metric tons FAOSTAT 16 , converted from cubic meters using a factor of 0.87 metric ton per cubic meter (from FAO 2020 33 , Table 2.3.1, average of conifer and non-conifer) Haul mode Diesel truck Assumed Haul distance 100 km one-way (round trip emissions assumed to be 1.75 times one-way emissions to account for empty return to the forest) 34–41 Fuel economy 2.56 km/l (6.2 mpg) in 2020. Lower to 2.4 km/l for 2005 and 1990 Davis and Boundy, 2022 42 , Table 2.16, converted using 129,000 Btu per gallon diesel Average load 20 metric tons (22 short tons) 39,40,40,43 Diesel emission factor 2.7 kg CO 2 /liter (10.21 kg CO 2 per gallon) US EPA 2014 44 , CO 2 only, does not include upstream emissions associated with fuel production Emissions per km 1.02 kg CO 2 /km in 2020, 1.12 kg CO 2 /km in 2005 and 1990 Calculated Emissions per metric ton-km based on 20 metric ton load and one-way haul distance 0.0512, 0.0562 and 0.0560 kg CO 2 per metric ton-km for 1990, 2005, and 2020 respectively Calculated Emissions associated with transporting pellets were estimated separately because they are not included in the list of commodities in SCTG 26, wood products. Details are provided in Supplementary Information. Co-products Produced by Wood Products Mills Wood products mills produce significant quantities of chips, sawdust, etc. that are used as raw materials by other facilities. These materials, however, are included in the list of wood products in SCTG 26 and the emissions associated with their transport are therefore included in the total for wood products. Non-Fiber, Non-Fuel Inputs The production of forest products requires a range of inputs besides wood fiber. The production and transport of these materials result in GHG emissions. Emissions associated with the production of nonfiber, nonfuel inputs are estimated elsewhere in this report. In this section, transport-related emissions attributable to these inputs are examined. Quantities of non-fiber, non-fuel inputs were estimated from life cycle assessment (LCA) studies identified in Supplementary Information. Data from the CFS were used to identify appropriate transport distances, also described in Supplementary Information. All transport was assumed to be by truck with a cargo load of 20 metric tons, allowing the use of emission factors in Table 8. Used Products After use, products are transported to recovery and/or disposal operations. Data on the quantities requiring transport were obtained from US EPA 46 . The last value in the EPA data was for 2018, so this was used as the 2020 data point in this study. The haul distance used was 362 km (225 mi), the value reported for 2017 in the CFS for SCTG 4112 10 , waste and scrap of paper and paperboard. Trucks were assumed to be the mode of transport and the truck emission factors for 20 metric ton loads in Table 8 were used. Emissions from Products During Use Few forest products emit GHGs during use, or cause GHGs to be emitted during use. Forest-based fuels, however, release methane and nitrous oxide when burned, and these are included in Scope 3 inventories. Biogenic CO 2 emissions are not included as emissions because these flows to the atmosphere are captured in the production accounting used to calculate changes in biogenic carbon stocks, discussed earlier in this report. The GHG emissions released when biomass is used as fuel by industry are accounted for as direct emissions (discussed above). Emissions from use of non-industrial use of wood-based fuels are calculated separately using the following approach.. Quantities of wood-based fuels consumed domestically by non-industrial users were estimated from US Forest Service data 22 . Pellet exports, which are used primarily for electricity production, were calculated from data produced by the US Department of Agriculture Global Agricultural Trade System (GATS) 47 . European Integrated Pollution Prevention and Control Bureau (IPCC) emission factors 11 were used to estimate methane and nitrous oxide emissions from non-industrial use of wood-based fuels and production of electricity from wood-based fuels. Details are provided in Supplementary Information. End-of-Life Emissions At end-of-life, forest products are recycled, landfilled, combusted, or diverted to a beneficial use (e.g., composting). Emissions associated with recycling occur in transporting recovered fiber and using it to produce new products. These emissions are accounted for elsewhere in this study. End-of-life GHG emissions from combustion (primarily municipal solid waste [MSW] waste-to-energy) as well as GHG emissions from composting are small and not included here. See Supplementary Information for additional discussion of these emissions. The calculations in this report, therefore, are limited to GHG emissions from MSW landfills attributable to discarded forest products. Landfill methane emissions attributable to forest products have been calculated as a fraction of total MSW landfill emissions reported in US EPA’s annual inventory 24 . To estimate the fraction of methane attributable to forest products, we separately modeled the decay of all decomposable fractions of MSW deposited in landfills since 1960. The data on deposits were taken from US EPA 46 . Parameter values for decay rates and nondegradable carbon were taken from the documentation for version 15 of US EPA’s Waste Reduction Model (WARM) 30 . The analysis of year-to-year decomposition and methane production is described in detail in Supplementary Information. Also discussed in Supplementary Information are factors that may affect the results of this approach. The landfill emissions calculated here address only forest products disposed in MSW landfills. Considerable quantities of discarded wood products, however, are disposed of in dedicated construction and demolition (C&D) debris landfills. The amounts of methane produced by wood products in these landfills is expected to be small and therefore is not included in the estimates developed for this study. Additional discussion of C&D debris landfills can be found in Supplementary Information. [1] See CORRIM.org for more information. [2] See CORRIM.org for more information. Declarations DATA AVAILABILITY The data used in this analysis is either contained or Supplementary Information or available via citations provided in Supplementary Information. ADDITIONAL INFORMATION Competing information statement: The authors declare no competing interests. FUNDING Reid Miner received funding from NCASI to undertake this project. AUTHOR CONTRIBUTION STATEMENT Reid Miner (corresponding author) performed much of the analysis and writing associated with carbon in forest products, emissions associated with producing and harvesting wood, upstream emissions associated with non-fiber, non-fuel inputs, converting emissions, transport emissions, emissions from the management of industry wastes, emissions from products use and end-of-life emissions. Dr. Barry Malmberg performed the calculations and prepared the material addressing Scope 1 combustion-related emissions and Scope 2 emissions. In addition, he participated in the calculation of converting emissions. Adam Costanza prepared many the factors used to calculate Scope 3 life cycle emissions associated with non-fiber, non-fuel inputs, Scope 3 electricity-related emissions and transport-related emissions. Dr. Steve Prisley prepared the material describing impacts of forest ecosystem carbon. AUTHOR INFORMATION *Corresponding Author NCASI, 1513 Walnut Street, Suite 200, Cary, NC, USA 27511 Phone (919) 600-1022 Email: [email protected] Dr. Barry Malmberg NCASI email: [email protected] Adam Costanza NCASI Email: [email protected] Dr. Steve Prisley Prisley Forest Analytics LLC mail: [email protected] References Heath, L. S. et al. Greenhouse Gas and Carbon Profile of the U.S. Forest Products Industry Value Chain. Environ. Sci. Technol. 44 , 3999–4005 (2010). WBCSD & WRI. GHG Protocol Corporate Accounting and Reporting Standard . https://ghgprotocol.org/corporate-standard (2004). WBCSD & WRI. Corporate Value Chain (Scope 3) Standard | GHG Protocol . https://ghgprotocol.org/corporate-value-chain-scope-3-standard (2011). United States Environmental Protection Agency (EPA). Annexes to Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022 . https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2022 (2024). Oswalt, S. N., Smith, W. B., Miles, P. D. & Pugh, S. A. Forest Resources of the United States, 2017: a technical document supporting the Forest Service 2020 RPA Assessment. Gen. Tech. Rep. WO-97. Washington, DC: U.S. Department of Agriculture, Forest Service, Washington Office. 97 , (2019). Kim, T., Wear, D., Coulston, J. & Li, R. Forest land use responses to wood product markets. Forest Policy and Economics 93 , 45–52 (2018). United States Environmental Protection Agency (EPA). Emissions & Generation Resource Integrated Database (eGRID). https://www.epa.gov/egrid (2020). United States Environmental Protection Agency (EPA). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022 . https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2022 (2024). American Forest and Paper Association (AF&PA). 2020 Statistics, Paper, Paperboard & Pulp . (2021). United States Census Bureau. Commodity Flow Survey Tables. Census.gov https://www.census.gov/programs-surveys/cfs/data/tables.html (2025). IPCC (Intergovernmental Panel on Climate Change). 2006 IPCC Guidelines for National Greenhouse Gas Inventories . https://www.ipcc-nggip.iges.or.jp/public/2006gl/index.html (2006). IPCC (Intergovernmental Panel on Climate Change). Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change . https://www.ipcc.ch/report/ar5/wg1/ (2013). WBCSD & WRI. GHG Protocol Calculation Tools and Guidance. https://ghgprotocol.org/calculation-tools-and-guidance?ap3c=IGXmCH6WDeDPomoEAGXmCH6mIt-Db9NCNH00dmje0ZqebCmgPw#sector_specific_tools_id (2009). United States Energy Information Administration (EIA). Manufacturing Energy Consumption Survey (MECS). https://www.eia.gov/consumption/manufacturing/. United States Environmental Protection Agency (USEPA). Greenhouse Gas Reporting Program (GHGRP). https://www.epa.gov/ghgreporting (2014). United Nations Food and Agriculture Organization (FAO). FAOSTAT. https://www.fao.org/faostat/en/#home. NCASI. Scope 3 GHG Screening Tool, version 1.1a. NCASI (2025). National Renewable Energy Laboratory (NREL). Life Cycle Greenhouse Gas Emissions from Electricity Generation: Update . (2021). Whitaker, M., Heath, G. A., O’Donoughue, P. & Vorum, M. Life Cycle Greenhouse Gas Emissions of Coal-Fired Electricity Generation. Journal of Industrial Ecology 16 , S53–S72 (2012). NCASI & International Finance Corporation of the World Bank (IFC). Forest Industry Carbon Assessment Tool (FICAT). NCASI (2025). American Forest and Paper Association (AF&PA). 2019 Statistics, Paper, Paperboard & Pulp . (2020). Howard, J. L. & Liang, S. U.S. timber production, trade, consumption, and price statistics, 1965-2017. Forest Service Research Data Archive https://doi.org/10.2737/RDS-2018-0035 (2019). NCASI. Unpublished Survey Data on Solid Waste Generation Rates . (2025). United States Environmental Protection Agency (EPA). Annexes to Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020 . https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2020 (2022). Campbell, A. Recycling and disposing of wood ash, TAPPI JOURNAL, September 1990, Vol. 73(9). TAPPI Journal 73 , 141–146 (1990). NCASI. A Summary of Available Data on the Chemical Composition of Forest Products Industry Solid Wastes . (1999). Malyan, S. K. et al. Methane production, oxidation and mitigation: A mechanistic understanding and comprehensive evaluation of influencing factors. Science of The Total Environment 572 , 874–896 (2016). NCASI. Solid Waste Management and Disposal Practices in the US Paper Industry−1995 . (1999). NCASI. Solid Residual Generation and Beneficial Use, and Wastewater Treatment Performance and Practices of the North American Pulp and Paper Industry . (2019). United States Environmental Protection Agency (EPA). Documentation for Greenhouse Gas Emission and Energy Factors Used in the Waste Reduction Model (WARM) - Management Practices Chapters . https://www.epa.gov/sites/default/files/2020-12/documents/warm_management_practices_v15_10-29-2020.pdf (2020). Wang, X., Padgett, J. M., De la Cruz, F. B. & Barlaz, M. A. Wood Biodegradation in Laboratory-Scale Landfills. Environ. Sci. Technol. 45 , 6864–6871 (2011). United States Environmental Protection Agency (EPA). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020 . https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2020 (2022). United Nations Food and Agriculture Organization (FAO), I. and U. N. Forest Product Conversion Factors . (FAO, ITTO and United Nations ;, 2020). Milota, M., Science, W. & Hall, R. Life Cycle Assessment for the Production of Southeastern Softwood Lumber . (2020). Milota, M., Science, W. & Hall, R. Life Cycle Assessment for the Production of Pacific Northwest Softwood Lumber . https://corrim.org/wp-content/uploads/2020/06/CORRIM-AWC-PNW-Lumber.pdf (2020). Oneil, E. & Puettmann, M. E. A Life-Cycle Assessment of Forest Resources of the Pacific Northwest, USA*. https://doi.org/10.13073/FPJ-D-17-00011 (2017) doi:10.13073/FPJ-D-17-00011. Puettmann, M., Kaestner, D. & Taylor, A. Life Cycle Assessment for the Production of Southeast Softwood Plywood . (2020). Bergman, R. D. & Bowe, S. A. Life-Cycle Inventory of Hardwood Lumber Manufacturing in the Northeast and North Central United States. Barrett, S., Bolding, C. & Munsell, J. Characteristics of Logging Businesses across Virginia’s Diverse Physiographic Regions. Forests 8 , 468 (2017). Conrad, J., Greene, W. & Hiesl, P. The Evolution of Logging Businesses in Georgia 1987–2017 and South Carolina 2012–2017. Forest Science 64 , (2018). Conrad, J. L. Log truck insurance premiums, claims, and safety practices among logging businesses in the US South. International Journal of Forest Engineering 34 , 204–215 (2023). Davis, S. C. & Boundy, R. G. Transportation Energy Data Book: Edition 40. (2022). Conrad, J. L. Evaluating Profitability of Individual Timber Deliveries in the US South. Forests 12 , 437 (2021). United States Environmental Protection Agency (EPA). Emission Factors for Greenhouse Gas Inventories. (2014). United States Department of Transportation (US DOT). Class I Rail Freight Fuel Consumption and Travel. Class I Rail Freight Fuel Consumption and Travel https://www.bts.gov/content/class-i-rail-freight-fuel-consumption-and-travel (2025). United States Environmental Protection Agency (EPA). Advancing Sustainable Materials Management: 2018 Tables and Figures . https://www.epa.gov/sites/default/files/2021-01/documents/2018_tables_and_figures_dec_2020_fnl_508.pdf (2020). United States Department of Agriculture (USDA). FAS - Global Agricultural Trade System (GATS). https://apps.fas.usda.gov/gats/default.aspx. Additional Declarations No competing interests reported. Supplementary Files SupplementaryInformationDocumantforMineretal.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 02 Feb, 2026 Reviews received at journal 30 Jan, 2026 Reviewers agreed at journal 20 Jan, 2026 Reviews received at journal 13 Jan, 2026 Reviewers agreed at journal 08 Jan, 2026 Reviewers agreed at journal 05 Jan, 2026 Reviews received at journal 02 Jan, 2026 Reviews received at journal 02 Jan, 2026 Reviewers agreed at journal 01 Jan, 2026 Reviewers agreed at journal 31 Dec, 2025 Reviewers agreed at journal 30 Dec, 2025 Reviewers agreed at journal 24 Dec, 2025 Reviewers invited by journal 24 Dec, 2025 Editor invited by journal 18 Dec, 2025 Editor assigned by journal 09 Dec, 2025 Submission checks completed at journal 09 Dec, 2025 First submitted to journal 05 Dec, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Miner","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/0lEQVRIiWNgGAWjYBAC+wbGBgkGA4bENhDvAxCzsRPQYnAApKWCoRikhXEGSAszQS0MDBIMZxjqG4AcZh6QEEEtx5sbbzC2MeT2STcf+2zza5s8HzMD44ePOXj80nOw2QKkpU3mWPLs3L7bhm3MDMySM7fh1mInkdgmAdYikWPMnNtzmxGohY2ZF48WY/mHQC3/gCEmkf+Z2bLntj1BLYYzGMG2ALXkMDMz/LidSFCLwZnEZgugeiBKM2bsbbid3MbM2IzXLwbHjz+88bHNJnH+jOTHDD/+3Lad39588MNHPFrAIAEYNWDACE4DjA0E1KOAP6QoHgWjYBSMgpECANdBUKWGCa/KAAAAAElFTkSuQmCC","orcid":"","institution":"National Council for Air and Stream Improvement","correspondingAuthor":true,"prefix":"","firstName":"Reid","middleName":"A.","lastName":"Miner","suffix":""},{"id":565483550,"identity":"2138f41d-b5dc-4f3d-9f71-c2f2eabb49ce","order_by":1,"name":"Barry Malmberg","email":"","orcid":"","institution":"National Council for Air and Stream 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1","display":"","copyAsset":false,"role":"figure","size":54911,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eChart 1\u003c/strong\u003e.\u0026nbsp; Net Forest Stock Change in Timberlands and Harvests for Eight US Regions\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8290322/v1/dd90ab09f0b55e1b0b88dece.png"},{"id":99323059,"identity":"1c1e78c0-e0c6-48bc-9749-262981587606","added_by":"auto","created_at":"2025-12-31 16:44:50","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1537765,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8290322/v1/bd442f62-bd80-4ccf-b5a7-80507b08cb6f.pdf"},{"id":99314221,"identity":"8b54549d-31df-4188-b395-ca8e98bb060f","added_by":"auto","created_at":"2025-12-31 16:21:00","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":1831051,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryInformationDocumantforMineretal.docx","url":"https://assets-eu.researchsquare.com/files/rs-8290322/v1/3815d90a5cc58d3a1f42e231.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Greenhouse Gas and Carbon Profile of the US Forest Products Industry: 1990 to 2020","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eFifteen years ago, the National Council for Air and Stream Improvement, Inc. (NCASI) collaborated with the US Forest Service to develop a profile of US forest products industry greenhouse gas (GHG) emissions and sinks in 1990 and 2005 \u003csup\u003e1\u003c/sup\u003e. Much has changed since the publication of that study. Energy sources used to power industry and produce electricity have become less GHG-intensive. The production of many forest products has decreased while recovery rates of used products have increased, and many other changes have occurred. In addition, methods used to estimate emissions have evolved. In this study, the profile published in 2010 is updated by adding data for 2020. In addition, earlier estimates are improved by applying the most appropriate data and methods available today. This analysis, like that published in 2010, is based on annual inventory accounting which includes all emissions from the value chain occurring in the year of the inventory, regardless of when the product responsible for the emissions was produced. This contrasts with life cycle assessment accounting which normally includes all emissions from the value change attributed to a single year\u0026rsquo;s production, regardless of when the emissions occur.\u003c/p\u003e\n\u003cp\u003eAn attempt has been made to include all relevant emission categories addressed in the GHG Protocol Corporate Standard, which covers Scope 1 and 2 emissions \u003csup\u003e2\u003c/sup\u003e and the GHG Protocol Value Chain (Scope 3) Standard \u003csup\u003e3\u003c/sup\u003e. For the purposes of this report, Scope 1 emissions are those from manufacturing and converting operations in the forest products value chain. Scope 2 emissions are those released by producers of electricity and steam purchased by the forest products industry. Scope 3 emissions are all other emissions in the forest products industry value chain. In addition, we characterize the net exchange of biogenic carbon between the atmosphere and the US forest products value chain. For a complete description of the emissions Scope concept, see the GHG Protocol Corporate Standard \u003csup\u003e2\u003c/sup\u003e and Supplementary Information.\u0026nbsp;\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003e\u003cstrong\u003eBiogenic Carbon\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBiogenic carbon resides in three pools in the forest products industry value chain: the forest, products in use, and products in landfills. If the total amount of biogenic carbon in these three pools is growing, it means that there has been a net transfer of carbon from the atmosphere into the stocks of carbon stored in these pools (i.e., net carbon removals). Conversely, if the total carbon stocks in these pools is declining, it means that there are net transfers of carbon from the value chain to the atmosphere (i.e., net carbon emissions). While the trends in carbon stocks in the individual pools provide important information, it is only by summing the changes across all three pools that one can calculate the net exchange of biogenic carbon between the atmosphere and the forest products industry value chain.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eForest Ecosystem Carbon\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor the previous GHG and carbon profile in Heath et. al. \u003csup\u003e1\u003c/sup\u003e, the US Forest Service examined the question of industry impacts on forest ecosystem carbon at a level of detail not possible with publicly available data. This previous analysis found that:\u003c/p\u003e\n\u003cp\u003e\u0026ldquo;Because the complexity of wood flows precludes a precise estimate of forest carbon impacts attributable to the industry, and because carbon stocks on industry-owned lands appear relatively stable, we assume that forest industry landowners manage their forests so that growth and removals are equal over time, resulting in an average net forest carbon change of zero \u003csup\u003e1\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eSince the Heath et. al. study, domestic harvesting first declined then rebounded so that by 2020, it was nearly at the same level as 2005 but still below 1990 levels \u003csup\u003e4\u003c/sup\u003e suggesting that the conclusion from Heath et. al. remains appropriate.\u003c/p\u003e\n\u003cp\u003eAdditional insights into the impact of harvesting on forest carbon stocks can be found in data from Oswalt et al. \u003csup\u003e5\u003c/sup\u003e, shown in Chart 1. In 2016, stocks in seven of the eight regions reported by the Resources Planning Act Assessment were increasing, with losses in the Intermountain region due to high levels of mortality from fire and insect damage. The regions with the highest increases in forest stock were the areas with highest harvest levels, as shown in Chart 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChart 1\u003c/strong\u003e. \u0026nbsp; Net Forest Stock Change in Timberlands and Harvests for Eight US Regions \u003csup\u003e5\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eThe harvesting and forest data available since 2005, therefore, provide no reason to suspect that carbon stocks are declining on the land that produces wood for the forest products industry. Indeed, all indications are that these stocks are increasing, resulting in net removals of CO\u003csub\u003e2\u003c/sub\u003e from the atmosphere. Furthermore, research continues to show that the demand for wood \u0026ldquo;reduce[s] transitions of forests to all other rural land uses as well as to developed land uses \u003csup\u003e6\u003c/sup\u003e.\u0026rdquo; As a result, for purposes of this study, as in Heath et al. \u003csup\u003e1\u003c/sup\u003e, it is concluded that net emissions of biogenic carbon attributable to the forest products industry\u0026rsquo;s activities in the forest can be conservatively assumed to be zero for the period covered by the analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCarbon in Forest Products\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEstimates of annual changes in carbon held in forest products in-use and in-landfills, published by EPA\u003csup\u003e4\u003c/sup\u003e, are shown Table 1. \u0026nbsp;The amount of carbon leaving the pool of products in use is relatively constant compared to the year-to-year change in inputs to this pool (i.e., new production). As a result, changes in industry production have a large impact on the annual changes in carbon stocks in use. Indeed, during sharp downturns in industry production, such as in 2008, total stocks of carbon in products in use can decline. Net reductions in stocks of carbon in products in use are relatively rare, however, especially for wood products because they remain in use for much longer periods than paper products.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe stocks of carbon in the products-in-use pool grew by 14.9 million metric tons C in 1990, 11.6 million metric tons C in 2005, and 8.8 million metric tons C in 2020. The primary reason for the decline in annual growth between 1990 and 2005 was decreasing domestic production of forest products.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe annual variability in changes in carbon stocks in landfills is much smaller than changes in stocks of carbon in products in use. This is primarily because inputs to landfill carbon stocks are far less variable than inputs to the pool of products in use. Net additions to landfill carbon stocks in 1990, 2005, and 2020 were 18.8, 17.3, and 17.6 million metric tons C per year, respectively.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;1.\u0026nbsp;\u003c/strong\u003eNet Additions to US Product Carbon Stocks in 1990, 2005, and 2020 \u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"450\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 107px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" style=\"width: 343px;\"\u003e\n \u003cp\u003eNet C Additions, Million Metric Tons C/yr\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003e1990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e2005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 126px;\"\u003e\n \u003cp\u003e2020\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003eIn Use\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003e14.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e11.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 126px;\"\u003e\n \u003cp\u003e8.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003eIn Landfills\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003e18.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e17.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 126px;\"\u003e\n \u003cp\u003e17.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003e33.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e28.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 126px;\"\u003e\n \u003cp\u003e26.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDirect (Scope 1) Emissions from Fuel Combustion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe fuel-related direct emissions in 1990, 2005, and 2020 are shown in Table 2.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e. Direct Fuel Combustion-Related Emissions from the Forest Product Industry\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"546\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 139px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" style=\"width: 407px;\"\u003e\n \u003cp\u003eMillion Metric Tons CO\u003csub\u003e2\u003c/sub\u003ee\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 139px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 125px;\"\u003e\n \u003cp\u003e1990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e2005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e2020\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 139px;\"\u003e\n \u003cp\u003ePulp and Paper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 125px;\"\u003e\n \u003cp\u003e66.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e55.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 139px;\"\u003e\n \u003cp\u003eWood Products\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 125px;\"\u003e\n \u003cp\u003e3.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e4.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 139px;\"\u003e\n \u003cp\u003eConverting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 125px;\"\u003e\n \u003cp\u003e7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e13.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e5.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 139px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 125px;\"\u003e\n \u003cp\u003e78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e74.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e43.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eBetween 1990 and 2020, direct GHG emissions for the US paper, paperboard, and market pulp sector declined from 66.9 to 33.0 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee, a reduction of 51%. Even over the shorter period of 2005 to 2020, emissions were reduced by 40%.\u003c/p\u003e\n\u003cp\u003eDirect GHG emission intensity for the US pulp and paper sector (i.e., tons of emissions per ton of production) was reduced by 48% between 1990 and 2020, from 0.83 metric tons CO\u003csub\u003e2\u003c/sub\u003ee per metric ton production in 1990 to 0.43 in 2020.\u003c/p\u003e\n\u003cp\u003eChanges in direct fuel combustion-related emissions from wood products mills and converting operations are related primarily to changes in production.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eApproximately three-quarters of the 2020 direct emissions from fuel combustion are associated with the pulp, paper, and paperboard primary manufacturing sector. The industry\u0026rsquo;s fuel combustion\u0026ndash;related emissions in 2020 were reduced by 44% since 1990 and 41% since 2005.\u003c/p\u003e\n\u003cp\u003eBiogenic carbon dioxide emissions have ranged between 135.7 and 144.7 million metric tons per year over the last 30 years. These are not counted in GHG emissions totals, however, because they are included in the mass balance stock change calculations performed on biogenic carbon, described above and in detail in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmissions from Producers of Purchased Electricity (Scope 2)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIndirect emissions associated with purchases of electricity and steam (Scope 2, under the GHG protocol \u003csup\u003e2\u003c/sup\u003e) are shown in Table 3. Emissions reductions from 1990 to 2020 were approximately 50% for both gross- and net- electricity\u0026ndash;based estimates. The same is true for the period of 2005 to 2020. Emissions associated with net energy purchases (including steam) were 20.0%, 16.6%, and 17.7% lower than those based on gross purchases (including steam) in 1990, 2005, and 2020, respectively. Emissions attributable to purchased steam account for about 9% (range from 5 to 13%) of emissions from gross purchases of steam and electricity.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e. Indirect Scope 2 Emissions Attributable to Electricity and Steam Purchases in the US Paper, Paperboard, and Market Pulp Sector\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"594\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 258px;\"\u003e\n \u003cp\u003eMillion Metric Tons CO\u003csub\u003e2\u003c/sub\u003ee\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e1990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e2005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e2020\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003ePulp and Paper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eBased on Gross Purchases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e32.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e33.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e16.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eBased on Net Purchases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e24.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e24.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e11.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eWood Products\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eBased on Gross Purchases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e12.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e16.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e9.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eBased on Net Purchases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e11.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e15.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e8.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eConverting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eBased on Gross Purchases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e19.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e19.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e10.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eBased on Net Purchases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e19.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e19.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e10.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eTotal Forest Products Industry\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eBased on Gross Purchases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e64.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e68.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e36.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 336px;\"\u003e\n \u003cp\u003eBased on Net Purchases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e55.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e59.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e31.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEmissions intensity based on gross purchased electricity (not including steam) declined from 0.38 to 0.19 tons CO\u003csub\u003e2\u003c/sub\u003e per ton production from 1990 to 2020 while intensity based on net purchased electricity declined from 0.30 to 0.15 tons CO\u003csub\u003e2\u003c/sub\u003e per ton production.\u003c/p\u003e\n\u003cp\u003eMuch of the reduction in emissions associated with purchased electricity have been attributable to the greening of the grid. Since 2005, there has been a 38% reduction in the national average purchased electricity GHG emission factor \u003csup\u003e7\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFor wood product mills, Scope 2 associated with gross purchased electricity in 2020 were 43% lower than in 2005 and 27% lower than in 1990. Reductions in emissions associated with net electricity are similar.\u003c/p\u003e\n\u003cp\u003eOn average, 93% (ranging from 91 to 95%) of the converting emissions associated with purchased electricity are in the pulp and paperboard sector.\u003c/p\u003e\n\u003cp\u003eIn 2020, the pulp, paper, and paperboard sector accounted for 45% of all Scope 2 emissions. Wood products accounted for 25%. The converting sector accounted for 30%, almost all of which was associated with converting paper and paperboard. Between 1990 and 2020, these emissions were reduced by 47%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eScope 3 Emissions Associated with Purchased Fossil Fuels and Electricity\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIndirect emissions associated with the production and transport of fossil fuels used by the US forest products Industry and by its suppliers of purchased electricity and steam are considered Scope 3 emissions under the GHG Protocol \u003csup\u003e2\u003c/sup\u003e\u003csup\u003e,\u003c/sup\u003e \u003csup\u003e3\u003c/sup\u003e. Emissions associated with production and transport of fuels used by the industry are calculated to have been 11.1, 11.1, and 7.9 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee in 1990, 2005, and 2020 respectively. Corresponding emissions associated with fuels used by suppliers of electricity to the industry were 3.7, 4.7 and 4.0 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee in 1990, 2005 and 2020, respectively. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmissions Associated with Producing and Harvesting Wood\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGHG emissions are released in the production and harvesting of roundwood, for instance from equipment used for planting and harvesting. Chemicals may be used for weed and pest control and fertilization, and fire may also be used as a management tool. These emissions, which are considered to be Scope 1 for purposes of this report, are estimated to have been only 2.5, 2.3, and 2.1 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee in 1990, 2005 and 2020, respectively. The reductions in emissions reflect reductions in domestic roundwood production. Note that these do not include transport-related emissions, which are addressed elsewhere in this report. The estimate developed for this report is significantly higher than US EPA\u0026rsquo;s estimate of emissions associated with nitrogen fertilizer use in forestry \u003csup\u003e8\u003c/sup\u003e because EPA\u0026rsquo;s estimates do not include Scope 3 emissions associated with producing forest chemicals and fossil fuels used in forestry (which are included in this report\u0026rsquo;s estimates although they are classified as Scope 1).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUpstream Scope 3 Emissions Associated with Non-Fiber, Non-Fuel Inputs\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEmissions attributable to producing non-fiber, non-fuel inputs to manufacturing (e.g., additives, process chemicals) have declined over time primarily due to an overall reduction in production of paper and paperboard. The emissions associated with the paper and paperboard sector were 7.4, 8.4 and 6.2 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee in 1009, 2005 and 2020, respectively. Those in the wood products sector were 5.4, 6.5 and 5.2 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee in 1990, 2005 and 2020, respectively. These reductions in the paper and paperboard sector were especially large between 2005 and 2020 due to a 70% reduction in production of newsprint and printing/writing grades \u003csup\u003e9\u003c/sup\u003e, grades associated with higher upstream non-fiber, nonfuel emissions. This has caused the overall production-weighted average factor for the paper, paperboard, and market pulp sector to decline, being 94.6, 92.8, and 83.4 kg CO\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eper metric ton production in 1990, 2005, and 2020, respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmissions From Systems Managing Forest Products Industry Wastes\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePulp and paper mills as well as wood products mills can produce boiler ash and a variety of miscellaneous solid wastes. In addition, pulp and paper mills often generate wastewater treatment residuals and recovery area wastes. Sizable fractions of these solid wastes are landfilled, producing methane over time. The landfill emissions associated with landfilled solid wastes from the industry were 312, 394 and 386 thousand metric tons methane in 1990, 2005 and 2020, respectively. Using a global warming potential for methane of 25, these equate to emissions of 7.8, 9.9 and 9.7 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee in 1990, 2005 and 2020, respectively. Over 90% of the industry\u0026rsquo;s landfill methane emissions are attributable to pulp and paper mill wastes, and 50% to 60% of pulp and paper mill landfill emissions are attributable to wastewater treatment plant residuals.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSmall amounts of methane and nitrous oxide emissions are also associated with the treatment of wastewater from pulp and paper mills. These totaled 1.6, 1.4 and 0.9 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee in 1990, 2005 and 2020, respectively.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTransport Emissions in the Forest Products Industry Value Chain\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTransport emissions along the forest products industry value chain are shown in Table 4, Transport-related emissions in 2020 were 10% lower than in 1990 and 18% lower than in 2005. The changes over time reflect primarily (a) changes in the ton-km values reported in the Commodity Flow Survey \u003csup\u003e10\u003c/sup\u003e and (b) improvements in transport fuel efficiency. Approximately 73% of these emissions are associated with transport of products. The results reflect multiple sequential shipments of the same fiber as it is transformed from raw material leaving the forest into final products at the retail level.\u003c/p\u003e\n\u003cp\u003eEmissions associated with transport of roundwood are also large because, even though the transport distances are relatively small, logs contain a significant amount of water and the vehicles return to the forest empty, doubling the one-way haul distance attributed to each load. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4.\u003c/strong\u003e Emissions Attributable to Transport in the US Forest Products Industry Value Chain\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 348px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003eMillion Metric Tons CO\u003csub\u003e2\u003c/sub\u003ee\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e1990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e2005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e2020\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eRaw Materials\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eAll roundwood, including firewood\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e4.37\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e4.02\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e3.36\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eRecovered fiber (shown as used products below)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003eSee used products\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003ePaper and paperboard non-fiber, non-fuel inputs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.17\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.18\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.12\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eWood product non-fiber, non-fuel inputs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.01\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.02\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.01\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eProducts\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eWood products\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e7.37\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e7.52\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e6.01\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003ePaper and paperboard\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e5.20\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e5.94\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e5.47\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003ePaper articles\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e1.49\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e2.31\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e1.91\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003ePrinted materials\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e1.58\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e1.84\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.83\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eWood-based pellets\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.06\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.40\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eUsed Products\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eUsed Products\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e1.57\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e1.84\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e1.44\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e21.8\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e23.7\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e19.5\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eFraction of 1990 total emissions\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e1.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.90\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 348px;\"\u003e\n \u003cp\u003eFraction of 2005 total emissions\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.82\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmissions Resulting from Use of Forest Products\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEmissions attributable to the use of forest products are limited to those from the use of wood-based fuels. Emissions from the industrial use of wood-based fuels are almost entirely from the forest products industry and are included in Table 2 above. The nonindustrial GHG emissions associated with the use of wood-derived fuels produced in the US were 9.1, 5.5 and 5.9 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee in 1990, 2005 and 2020, respectively.\u003c/p\u003e\n\u003cp\u003eThese emissions are dominated by methane emissions from residential use of wood for energy. Residential firewood accounted for 84% of nonindustrial wood energy emissions in 2017 but decreased through the 1990s due to a decline in residential use of wood for fuel. \u0026nbsp; Attributing all firewood emissions to the forest products industry value chain implies that everyone cutting and selling firewood is part of that value chain. The appropriateness of this approach could be questioned, especially in areas where firewood is collected by individuals for their own use.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmissions from Forest Product End-of-Life\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe landfilling of used forest products at end-of-life results in methane emissions. \u0026nbsp;Methane emissions attributable to landfilled forest products amounted to 78.6, 51.0 and 30.5 million metric tons CO\u003csub\u003e2\u003c/sub\u003ee in 1990, 2005 and 2020, respectively. \u0026nbsp; Approximately 90% to 95% of these emissions are attributable to paper and paper products. Except for methane emissions from MSW landfills, end-of-life emissions are expected to be small, as discussed in Supplementary Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSummary of Forest Product Industry Value Chain GHG Emissions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe emissions from the forest product industry value chain for 1990, 2005 and 2020 are summarized in Table 5. The results are presented both in terms of gross and net emissions. Because stocks of biogenic carbon in the value chain are increasing, there is a net transfer of CO\u003csub\u003e2\u003c/sub\u003e from the atmosphere into the value chain which can be expressed as a negative emission of CO\u003csub\u003e2\u003c/sub\u003e. This net removal of CO\u003csub\u003e2\u003c/sub\u003e from the atmosphere is considered in calculating net GHG emissions but not gross GHG emissions. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5.\u003c/strong\u003e Gross and Net Emissions Attributable to the Forest Products Industry Value\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"624\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"bottom\" style=\"width: 287px;\"\u003e\n \u003cp\u003eEmission Category\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"bottom\" style=\"width: 230px;\"\u003e\n \u003cp\u003eMillion Metric Tons CO\u003csub\u003e2\u003c/sub\u003ee\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e% of 2020 Gross Emissions\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e2005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003e2020\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eBiogenic CO\u003csub\u003e2\u003c/sub\u003e Accounting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eChanges in forest ecosystem carbon stocks\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e0*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e0*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003eNot Applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eChanges in product carbon stocks\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e123.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e106.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e96.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003eNot Applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eNet Emissions of Biogenic CO\u003csub\u003e2\u003c/sub\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026minus;123.8**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e\u0026minus;106.0**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e\u0026minus;96.8**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003eNot Applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eGHGs Other Than Biogenic CO\u003csub\u003e2\u003c/sub\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eScope 1 fuel combustion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e78.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e74.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e43.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e25%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eScope 2 (based on gross energy purchases)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e64.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e68.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e36.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e21%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eManagement of Mill Wastes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e9.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e11.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e10.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e6%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eTransport\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e21.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e23.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e19.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e11%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eUpstream \u0026ndash; Purchased electricity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e3.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e4.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e2%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eUpstream \u0026ndash; Non-fiber input production\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e12.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e14.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e11.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e7%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eUpstream \u0026ndash; Fossil fuel production and transport\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e11.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e11.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e7.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e5%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eProduct use (84 to 96% residential wood fuel emissions)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e9.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e5.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e5.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e3%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eWood supply production\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e2.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e2.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e1%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eProduct end-of-life\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e78.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e51.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e30.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e18%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eGross value chain emissions***\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e291.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e267.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e172.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e100%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 287px;\"\u003e\n \u003cp\u003eNet value chain emissions\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e167.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e161.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003e75.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" style=\"width: 624px;\"\u003e\n \u003cp\u003e* Based on a conservative analysis of forest carbon stocks as described in Section 2 of this paper.\u003c/p\u003e\n \u003cp\u003e** Negative values indicate a net removal of CO\u003csub\u003e2\u003c/sub\u003e from the atmosphere.\u003c/p\u003e\n \u003cp\u003e*** Excluding net biogenic CO\u003csub\u003e2\u003c/sub\u003e emissions\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eScope 1 emissions from industry fuel combustion and Scope 2 emissions for manufacturing and converting operations accounted for 46.5% of the industry\u0026rsquo;s gross value chain emissions (i.e., not considering net removals of CO\u003csub\u003e2\u003c/sub\u003e from the atmosphere attributable to growth in stocks of biogenic carbon). An additional 18% were attributable to methane releases from landfilled forest products. The only other aspect of the value chain contributing more than 10% of total value chain emissions was transport, accounting for 11%.\u003c/p\u003e\n\u003cp\u003eChanges in GHG emissions and industry production are shown in Table 6. Between 1990 and 2020, gross emissions declined by 41% while production declined by less than 10%. During the period of 2005 to 2020, gross emissions declined by 36% while production decreased by 21%.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLike gross emissions, net emissions (which include the effects of changes in stocks of forest carbon) have declined over time, with net emissions in 2020 being 55% below 1990 and 53% below 2005 net emissions. The calculations of net emissions of forest carbon rely on the observation, consistent with available data, that forest carbon stocks on land used to produce wood for the industry are stable or increasing. This justifies a conservative assumption of zero net change in forest carbon stocks in the calculations. \u0026nbsp; The primary reason for the decline in annual additions to stocks of carbon in products in use between 1990 and 2005 was decreasing domestic harvest. Between 1990 and 2006 the decline in domestic wood production was gradual, but the 2007\u0026ndash;2009 recession caused a dramatic downturn in harvesting of wood, which had the expected impact on changes in stocks of carbon in products in use. Wood production and in-use carbon stocks subsequently increased. A large fraction of the growth in carbon stocks in products in use is attributable to wood products (See Supplementary Information).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe factors contributing most to overall reductions in gross value chain emissions are examined in Table 7. Reductions in emissions associated with fuel combustion, purchased electricity and landfilling of used products at end-of-life accounted for 93% of the reductions between 1990 and 2020 and 88% of the reductions between 2005 and 2020.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe reductions in fuel combustion-related emissions have been due primarily to increased use of biomass fuel, reduced use of coal and changes in production. \u0026nbsp;In 1991, coal and other fossil fuels (primarily residual fuel oil) represented 13% and 7% of the on-site energy mix, respectively. By 2018, the coal contribution had decreased to 3%, and the contribution other fossil fuels had dropped to 1%. Between 1991 and 2018, the natural gas energy contribution increased from 20% to 26%, and the biomass energy contribution increased from 53% to 63%. These changes contributed to GHG reductions on both intensity and absolute bases for the US pulp and paper industry. Additional discussion of these emissions and the factors affecting them can be found in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 6.\u003c/strong\u003e Emissions and Production in 2020 Relative to Emissions in 1990 and 2005\u0026nbsp;\u003c/p\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"600\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eEmission Category\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 114px;\"\u003e\n \u003cp\u003eFraction of 1990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 108px;\"\u003e\n \u003cp\u003eFraction of 2005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eScope 1 fuel combustion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.59\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eScope 2 (based on gross energy purchases)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.53\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eManagement of Mill Wastes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e1.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.94\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eTransport\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.82\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eUpstream \u0026ndash; Purchased electricity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.86\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eUpstream \u0026ndash; Non-fiber input production\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.77\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eUpstream \u0026ndash; Fossil fuel production and transport\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.72\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eProduct use (84 to 96% residential wood fuel emissions)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eWood supply production\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.92\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eProduct end-of-life\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.60\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eTotal Gross Emissions\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.64\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003ePaper and Paperboard Production\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.79\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 378px;\"\u003e\n \u003cp\u003eWood Products Production\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.79\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe contribution of forest products to municipal solid waste (MSW) landfill methane releases has decreased over time. The primary reason is that paper and paperboard\u0026rsquo;s contribution to MSW has diminished. In 1990, paper and paperboard represented 30% of MSW landfill input. By 2018, this had dropped to 11.8%. In addition, the use of methane capture systems at MSW landfills has increased.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 7\u003c/strong\u003e. Contribution Analysis of Reductions in Gross GHG Emissions from the Forest Products Industry Value Chain\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eCategory\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003ePercentage of 1990 to 2020 Change\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003ePercentage of 2005 to 2020 Change\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eScope 1 Fuel Combustion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e29%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e32%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eScope 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e23%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e34%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eManagement of Mill Wastes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e-1%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e1%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eTransport\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e2%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e4%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eUpstream - Purchased Electricity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e0%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e1%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eUpstream - Non-fiber input production\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e1%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e4%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eUpstream - Fossil fuel production and transport\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e3%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e3%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eProduct Use (84 to 96% residential wood fuel emissions)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e3%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e0%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eWood Supply Production\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e0%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e0%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eProduct End-of-Life\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e40%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e21%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 384px;\"\u003e\n \u003cp\u003eTotal Gross Emissions\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 126px;\"\u003e\n \u003cp\u003e100%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e100%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"METHODS","content":"\u003cp\u003e\u003cstrong\u003eGreenhouse gas emission factors\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFuel-specific emission factors\u0026nbsp;\u003csup\u003e11\u003c/sup\u003e and GWPs\u0026nbsp;\u003csup\u003e12\u003c/sup\u003e published by the Intergovernmental Panel on Climate Change (IPCC) were used to convert subsector fuel use data into Scope 1 GHG emissions. However, in calculating CO\u003csub\u003e2\u003c/sub\u003ee emissions for CH\u003csub\u003e4\u003c/sub\u003e and N\u003csub\u003e2\u003c/sub\u003eO from biomass combustion, factors from GHG Protocol Calculation Tools\u0026nbsp;\u003csup\u003e13\u003c/sup\u003e were used because of their better representation of CH\u003csub\u003e4\u003c/sub\u003e and N\u003csub\u003e2\u003c/sub\u003eO emissions from US pulp and paper facilities. GHG emission factors for purchased electricity are taken from EPA\u0026rsquo;s Emissions \u0026amp; Generation Resource Integrated Database (eGRID) and are based on national averages for a given reporting year\u0026nbsp;\u003csup\u003e7\u003c/sup\u003e. Additional information on the sources and application of GHG emission factors is contained in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBiogenic Carbon\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eForest Ecosystem Carbon\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe US Forest Service develops periodic estimates of carbon stocks and fluxes in forest ecosystems. The US Environmental Protection Agency (US EPA) publishes these in its annual report on GHG emissions and sinks. Data for 1990 to 2020 were sourced from US EPA\u0026rsquo;s Inventory of Greenhouse Gases and Sinks: 1990\u0026ndash;2022 and the annexes to that inventory (US EPA 2024a; US EPA 2024b). The estimated net growth in carbon stocks in US forests in 2020 (208.6 million metric tons per year) is equivalent to removing 765 million metric tons CO\u003csub\u003e2\u003c/sub\u003e from the atmosphere annually (converting carbon to CO\u003csub\u003e2\u003c/sub\u003e equivalents (CO\u003csub\u003e2\u003c/sub\u003eeq.) by multiplying by 44/12). Although land use is not considered in the calculations for this report, these effects are small. Since 1990, the gains and losses of forest land in the US have resulted in a net loss of 5 to 7 million metric tons of forest ecosystem carbon per year (calculated from data in US EPA 2022a).\u003c/p\u003e\n\u003cp\u003eIt must be noted that the data on forest ecosystem carbon stocks include forests that are not used to produce industrial roundwood. Therefore, additional analyses, described in the results above, were performed. \u0026nbsp;The additional analysis found no evidence that carbon stocks are declining on wood-producing land.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCarbon Stored in Forest Products\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe changes in product carbon stocks are published by EPA in its annual inventory\u003csup\u003e4\u003c/sup\u003e. The stock change values for 1990 and 2005 in this update differ from those reported in Heath et all. 2010\u003csup\u003e1\u003c/sup\u003e. The primary reason is that, in recent inventories, US EPA updated its past estimates based on updated analysis by the US Forest Service. US EPA lowered the 1990 increase in stocks of in-use carbon to 14.9 from 17.7 million metric tons C. Likewise, the estimated increase for 2005 has been reduced to 11.6 from 12.1 in earlier US EPA inventory reports. The data and calculations for carbon in products in use and in landfills are described in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDirect (Scope 1) Emissions from Fossil Fuel Combustion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePulp and Paper Sector Data Sources\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAvailable government and industry data sets were synthesized for GHG emission calculations. The primary sources were:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eUS Energy Information Administration Manufacturing Energy Consumption Survey (MECS)\u003csup\u003e14\u003c/sup\u003e\u003c/li\u003e\n \u003cli\u003eAmerican Forest and Paper Association/American Paper Institute\u003csup\u003e9\u003c/sup\u003e. Because these data are collected annually and agree closely with the less frequently collected MECS data, the AF\u0026amp;PA data are used as the primary source of pulp and paper sector data in this analysis.\u003c/li\u003e\n \u003cli\u003eUS EPA Greenhouse Gas Reporting Program (GHGRP)\u003csup\u003e15\u003c/sup\u003e. Because the GHGRP only began in 2010, it was primarily used for comparison to other data sources. \u0026nbsp;\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThe use of these data sources and how they compare are discussed in detail in Supplemental Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eWood Products Data Sources\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCombustion-related emissions from wood product facilities were calculated from energy consumption data in MECS reports\u003csup\u003e14\u003c/sup\u003e from 1991 through 2018 and wood products production from FAOSTAT\u0026rsquo;s Forestry Production and Trade database\u0026nbsp;\u003csup\u003e16\u003c/sup\u003e. These data, and their use in calculating emissions, are discussed in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eConverting Operations Data Sources\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn most cases, wood and paper products require additional manufacturing to produce final products. There are many so-called converting operations. In the case of paper and paperboard products, these include printing, packaging, cutting, folding and gluing, and many others. In the case of wood products, these include converting wood into furniture, housing, and many other products. Because of the great variety in converting operations, any estimate of emissions associated with this part of the forest products industry value chain is subject to considerable uncertainty.\u003c/p\u003e\n\u003cp\u003eThis report contains estimates of emissions from some converting operations not included in the previous profile published by Heath et.al.\u003csup\u003e1\u003c/sup\u003e In addition, methods to estimate process energy-related emissions have been improved compared to the previous profile. As a result, there are differences between the estimates presented herein and those published in Heath et al. Previous estimates have been revised, however, using the updated methods, allowing a consistent comparison of emissions in 1990, 2005, and 2020.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFor this profile, estimates associated with converting were drawn primarily from EIA MECS data\u003csup\u003e14\u003c/sup\u003e. It is important to note that the EIA MECS data do not include all types of final processing operations performed on forest products. Also, for some EIA MECS sectors, materials other than forest products may be included in an NAICS code. Nonetheless, EIA MECS data provide a consistent series of data over time. The adjustments to, and use of, MECS data to calculate GHG emissions attributable to converting forest products into final products are described in detail in Supplementary Information. In the case of wood products, an additional contribution, not accounted for in MECS data, was calculated for converting wood products into housing. These data and methods used for calculating emissions from housing construction are also described in Supplementary Information. The analysis of converting emissions calculations indicates that these estimates are subject to considerable uncertainty, with estimated changes over time highly sensitive to the years selected for the comparison.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmissions from Producers of Purchased Electricity (Scope 2)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEmissions from purchased electricity are calculated by multiplying electricity purchases by the associated GHG emission factor. This study does not include carbon credits (e.g., renewable energy credits or RECS) purchased or sold by the forest products industry.\u003c/p\u003e\n\u003cp\u003eDetails on emission factor sources and GWPs used in calculations are provided above. Where possible, emissions estimates were shown in two ways, based on gross electricity purchases and net electricity purchases. Many inventory protocols, including the GHG Protocol, require estimates based on gross purchases\u0026nbsp;\u003csup\u003e2\u003c/sup\u003e. Estimates based on net purchases, however, can be more reflective of the amounts of electricity consumed in manufacturing. Where data allow, estimates are also shown that include purchases of steam. Gross purchases are used as the baseline estimates for this study. The previous GHG profile study\u003csup\u003e1\u003c/sup\u003e used net purchases to calculate Scope 2 emissions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePulp and Paper Sector Data Sources\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe same sources of data were used here as in the calculation of fuel combustion-related emissions, with the AF\u0026amp;PA being the primary data source. Additional discussion of the use of these sources and how they compare is provided in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eWood Product Mills Data Sources\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData on electricity purchases by wood products mills were obtained from EIA MECS\u003csup\u003e14\u003c/sup\u003e. These data, and their use in calculating emissions are described in Supplemental Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eConverting Operations Data Sources\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eScope 2 emissions for converting operations were estimated using the same approach as used for direct fuel combustion-related emissions (described previously). It is assumed that for converting operations, gross and net electricity purchases are equal; therefore, results are shown for gross purchases only. \u0026nbsp;Additional analysis of these emissions is shown in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eScope 3 Indirect Emissions Associated with the Production and Transport of Fossil Fuels Used by the US Forest Products Industry and by its Suppliers of Electricity\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGHGs are emitted in the production and transport of fuels used in the forest products industry. Upstream emission factors for the production and transport of fuels used by the industry were obtained from NCASI\u0026rsquo;s Scope 3 GHG Screening Tool, version 1.1a\u0026nbsp;\u003csup\u003e17\u003c/sup\u003e. These factors indicate that upstream GHG emissions associated with natural gas, oil, and coal are 19.8%, 16.1%, and 6.1% of the combustion emissions, respectively. Using these and EIA MECS data\u003csup\u003e14\u003c/sup\u003e to determine the mix of fuels in 1991, 2006, and 2018, a fuel-weighted ratio of upstream to combustions emissions was developed for each year and sector. The EIA survey years were used to represent 1990, 2008 and 2020 in the calculations for this report. These ratios remain relatively constant over this period for the pulp and paper converting, wood products, and wood products converting sectors at 0.20, 0.19 and 0.19 respectively. However, the factor for the pulp and paper sector went from 0.13 in 1991 and 2006 to 0.18 in 2018. due to an increased reliance on natural gas, for which upstream emissions are higher than for other fossil fuels.\u003c/p\u003e\n\u003cp\u003eEmissions in 1990, 2005, and 2020 associated with producing and transporting fuels used by suppliers of electricity were estimated using data from the National Renewable Energy Laboratory (NREL) on the ongoing upstream GHG emissions attributable to different types of power\u0026nbsp;\u003csup\u003e18\u003c/sup\u003e and information on the composition of the grid, as reported by eGRID\u0026nbsp;\u003csup\u003e7\u003c/sup\u003e. These data, and their application are discussed in Supplementary Information.\u003c/p\u003e\n\u003cp\u003eAlthough the NREL fact sheet\u0026nbsp;\u003csup\u003e18\u003c/sup\u003e suggests that its factors include transport emissions, the underlying literature source\u0026nbsp;\u003csup\u003e19\u003c/sup\u003e indicates that transport is not included in the factors so the factors were adjusted to include transport. The resulting Scope 3 factors based on the average composition of the grid were determined to be 38, 41 and 41 kg CO\u003csub\u003e2\u003c/sub\u003ee per MWh in 1990, 2005 and 2020 respectively. The details on calculation of these factors are shown in Supplemental Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmissions Associated with Producing and Harvesting Wood\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFactors that address these emissions have been developed for NCASI\u0026rsquo;s Scope 3 GHG Screening Tool, version 1.1a\u0026nbsp;\u003csup\u003e17\u003c/sup\u003e and have been used in this study. For purposes of this study, these are assumed to be Scope 1 Emissions.\u003c/p\u003e\n\u003cp\u003eFactors are available in the Screening Tool for production and harvesting of hardwood and softwood from the north and south US. The fraction of northern and southern, hardwood and softwood, were calculated from Table 39 in Oswalt et al.\u0026nbsp;\u003csup\u003e5\u003c/sup\u003e. Wood from other regions, which accounts for approximately 20% of US harvest, was ignored in calculating a weighted average factor for the US. The national weighted average factor was determined to be 0.0111 kg CO\u003csub\u003e2\u003c/sub\u003ee per kg dry wood harvested. \u0026nbsp;The weighted factor was assumed to apply equally to current and past wood production and harvesting. Emissions were therefore calculated by multiplying this factor by the quantity of roundwood production in 1990, 2005, and 2020. Roundwood production data were obtained from FAOSTAT\u0026nbsp;\u003csup\u003e16\u003c/sup\u003e. It was assumed that a cubic meter of green wood weighs 0.9 metric tons and all wood is 50% water.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUpstream Scope 3 Emissions Associated with Non-Fiber, Non-Fuel Inputs\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo estimate upstream emissions associated with non-fiber, non-fuel inputs (e.g., additives and process chemicals), NCASI divided the industry into product types. For each product type, upstream emissions associated with non-fiber inputs to manufacturing (not including fuels) were estimated using factors contained in the Forest Industry Carbon Assessment Tool (FICAT)\u0026nbsp;\u003csup\u003e20\u003c/sup\u003e, a model developed by NCASI for the International Finance Corporation of the World Bank. The list of product types and associated FICAT factors are shown in Supplemental Information. Production levels for pulp, paper, and paperboard were obtained from AF\u0026amp;PA statistical reports\u0026nbsp;\u003csup\u003e9,21\u003c/sup\u003e. Data on wood product output was obtained from Howard and Liang\u0026nbsp;\u003csup\u003e22\u003c/sup\u003e. The most recent wood products data available were for 2017; therefore, these were used to represent 2020.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmissions From Systems Managing Forest Products Industry Wastes\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePulp and Paper Mill Solid Wastes\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this report, methane emissions are calculated for four different wastes that may be disposed of in mill landfills: wastewater treatment residuals (WWTR), boiler ash, recovery area wastes, and other wastes. US EPA\u0026rsquo;s GHGRP includes calculation parameters for all of these wastes\u003csup\u003e15\u003c/sup\u003e. The GHGRP also includes parameter values for combined wastes from pulp and paper mills, but the estimates here assume the materials are landfilled separately. A comparison of estimates from separate and combined disposal are shown in Supplemental Information. Landfills receiving mill solid wastes are assumed to be lacking engineered methane collection systems.\u003c/p\u003e\n\u003cp\u003eEstimated landfill methane emissions associated with some of these wastes are available from EPA national inventory reports\u0026nbsp;\u003csup\u003e4\u003c/sup\u003e and from the GHGRP\u0026nbsp;\u003csup\u003e15\u003c/sup\u003e. The estimates in this report are based primarily on GHGRP methods and parameter values applied to data from industry sources. A comparison of EPA estimates, GHGRP reported estimates and those derived here is available in Supplemental Information.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eWastewater Treatment Residuals (WWTR)\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eFor estimating methane emissions attributable to WWTR in landfills, the first order decay model and default parameters in the GHGRP have been used. In specific;\u0026nbsp;\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003ea value of 0.12 kg organic C pr kg wet waste has been used for Degradable Organic Carbon (DOC),\u0026nbsp;\u003c/li\u003e\n \u003cli\u003ea value of 0.5 has been used for the fraction of DOC that will degrade in the landfill (DOCf),\u0026nbsp;\u003c/li\u003e\n \u003cli\u003ea value of 0.04 has been used for the first order decay rate (k) which is the default value for moderate climate,\u0026nbsp;\u003c/li\u003e\n \u003cli\u003ea value of 1.0 has been used for the fraction of degradable carbon subjected to anaerobic conditions (MCF),\u0026nbsp;\u003c/li\u003e\n \u003cli\u003ea value of 0.5 has been used to represent the fraction of degraded carbon that is converted to methane (F) and,\u003c/li\u003e\n \u003cli\u003ea value of 0.1 has been used to represent the fraction of generated methane that is oxidized naturally in the upper layers of the landfill before being released to the atmosphere (OX.)\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThe amounts of WWTR generated and landfilled were estimated from NCASI survey data to construct a series of annual values starting in 1960 and ending in 2020\u0026nbsp;\u003csup\u003e23\u003c/sup\u003e. Details are provided in Supplemental Information. Methane releases for each year from 1990 were estimated using the calculation approach in Subpart TT of the GHGRP\u003csup\u003e15\u003c/sup\u003e. \u0026nbsp;In Supplementary Information, the results of these calculations are compared to estimates derived from EPA national inventories\u003csup\u003e24\u003c/sup\u003e and from GHGRP data\u003csup\u003e15\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eBoiler Ash\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eLandfill methane emissions attributable to boiler ash are seldom estimated, being assumed to be small. This assumption is based on the low content of organic matter and, in the case of ash derived from wood and bark (hereafter referred to as simply wood ash), the high pH. The pH of wood ash is seldom below 10\u0026nbsp;\u003csup\u003e25,26\u003c/sup\u003e, while methane production is not favored at such a high pH\u0026nbsp;\u003csup\u003e27\u003c/sup\u003e. Given that companies are required to report ash landfills under the GHGRP, however, methane attributable to ash (wood and coal) disposal is estimated in this profile.\u003c/p\u003e\n\u003cp\u003eInformation on the quantities of ash produced by pulp and paper mills has been collected by NCASI since the mid-1990s\u0026nbsp;\u003csup\u003e23\u003c/sup\u003e. The use of these data to develop a time series of ash quantities is described in Supplemental Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe Subpart TT default parameter values used in the GHGRP to model methane emissions from boiler ash landfills are the same as those for WWTR except (a) a value of 0.06 kg organic C pr kg wet waste is used for Degradable Organic Carbon (DOC), and (b) a value of 0.03 is used for the first order decay rate (k) which is the default value for moderate climate.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe DOC values in the GHGRP Subpart TT rules are on a wet weight basis. Generation rates, however, are on a dry weight basis, requiring a factor to convert to as-disposed wet weight. Factors were developed, therefore, for converting from wet basis to dry basis. The development of these factors in described in Supplemental Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eRecovery Area Waste\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe recovery area of kraft pulp mills can produce several waste streams, often collectively called causticizing area waters. The three main wastes are lime mud, slaker grit, and green liquor dregs. These have not been included in past attempts to estimate methane emissions from mill landfills due to their relatively small quantities, low organic content, and typically elevated pH, which is generally not conducive to methane production. Nonetheless, the GHGRP contains parameter values for estimating landfill methane emissions attributable to these materials\u0026nbsp;\u003csup\u003e15\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNCASI survey\u0026nbsp;\u003csup\u003e23\u003c/sup\u003edata and published reports allow estimates of the past quantities of recovery waste produced and landfilled\u003csup\u003e28,29\u003c/sup\u003e. The data and calculations are shown in Supplemental Information. The parameter values used to model methane attributable to landfilled recovery area wastes were the same as for WWTR except (a) (a) a value of 0.025 kg organic C pr kg wet waste is used for Degradable Organic Carbon (DOC), and (b) a value of 0.03 is used for the first order decay rate (k) which is the default value for moderate climate.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eOther Waste from Pulp and Paper Mills\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe amounts of other waste being landfilled were derived using the same set of data as described for recovery area wastes. Calculations are shown in Supplemental Information. The parameter values used to model methane attributable to landfilled \u0026ldquo;other waste\u0026rdquo; were the same as for WWTR except (a) a value of 0.2 kg organic C pr kg wet waste is used for Degradable Organic Carbon (DOC), and (b) a value of 0.03 is used for the first order decay rate (k) which is the default value for moderate climate.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSolid Waste from Wood Products Facilities \u0026ndash; Lumber Mills\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWood products manufacturers often use wood-derived fuels that produce boiler ash. In addition, other wastes can be associated with wood handling and manufacturing operations. For this profile, therefore, methane emissions attributable to landfilling of ash and non-ash wastes were estimated. Non-ash wastes from wood products mills can include wood yard waste and manufacturing waste not suitable for use as fuel, as a raw material in the mill, or elsewhere.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe products and processes used at wood product plants vary. The available waste-related data, however, do not allow detailed differentiation between types of mills. Therefore, for this analysis, the wood products industry was divided into only two sectors: lumber and panels. The lumber category includes all softwood and hardwood lumber while the panel category includes all panels and engineered wood products.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eBoiler Ash\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThere are few survey data available on the amounts and types of solid waste from wood products mills. For this profile, NCASI calculated ash quantities based primarily on data on biomass energy consumption reported in EIA MECS surveys\u0026nbsp;\u003csup\u003e14\u003c/sup\u003e. The data and calculations are shown in Supplemental Information. Disposal methods were assumed to be the same as a pulp and paper mills. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe DOC values in GHGRP Subpart TT rules\u0026nbsp;\u003csup\u003e15\u003c/sup\u003e are on a wet weight basis. Generation rates, however, are on a dry basis, requiring a factor to convert them to as-disposed wet weight. The calculations were performed assuming that the average solids content for ash disposal from 1990 to 2020, equal to 83% (see Supplemental Information).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe parameter values used for modeling methane emissions attributable to landfilled ash from lumber mills were the same as those used for ash from pulp and paper mills.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eOther Wastes\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eStudies published by the Consortium for Research on Renewable Industrial Materials (CORRIM)\u003csup\u003e\u003csup\u003e[1]\u003c/sup\u003e\u003c/sup\u003e were used to develop a factor for estimating the amounts of non-ash solid waste landfilled at lumber mills. The use of these reports to calculate waste quantities is described in Supplemental Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe DOC values in GHGRP Subpart TT\u0026nbsp;\u003csup\u003e15\u003c/sup\u003e are on a wet weight basis; therefore, the dry weights estimated herein were converted to wet weights using a solids content of 85% based on the fact that the GHGRP DOC is taken from IPCC\u0026nbsp;\u003csup\u003e11\u003c/sup\u003e, where the associated water content is 15%.\u003c/p\u003e\n\u003cp\u003eThe GHGRP Subpart TT defaults for non-ash waste from wood and wood products mills are the same as for \u0026ldquo;other waste\u0026rdquo; from pulp and paper mills except a value of 0.43 kg organic C pr kg wet waste is used for Degradable Organic Carbon (DOC). This is more than twice the value for \u0026ldquo;other\u0026rdquo; wastes from pulp and paper mills (0.2). The default value for DOCf, however, is 0.5 for other wastes from both pulp and paper mills and lumber mills.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn considering these parameter values, it is important to consider that, at lumber mills, this\u0026nbsp;waste is primarily comprised of woody material that is not usable as raw material or fuel. The GHGRP default DOCf of 0.5, however, is not consistent with current research on the ultimate degradability of woody materials in anaerobic landfills\u0026nbsp;\u003csup\u003e30,31\u003c/sup\u003e. US EPA\u0026rsquo;s Waste Reduction Model (WARM), for instance, considers 88% of the carbon in lumber and 77% of the carbon in branches to be nondegradable in anaerobic landfills\u003csup\u003e30\u003c/sup\u003e. These are equivalent to DOCf values of 0.12 and 0.23, respectively. In this study, therefore, a value of 0.2 has been used for DOCf for other wastes from lumber mills. Additional analysis the value for woody waste DOCf is contained in Supplemental Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSolid Waste from Wood Products Facilities \u0026ndash; Panel Plants\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eBoiler Ash\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe approach to estimating methane attributable to landfilled boiler ash at panel plants was the same as described earlier for lumber mills. The calculations are shown in Supplemental Information. The fraction of ash landfilled was assumed to be the same as that for lumber mills, described previously.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUS EPA\u0026rsquo;s current default DOC values for boiler ash are based on as-disposed solids content. Therefore, for the calculations in this update, DOC was converted to a dry basis using the same assumptions for solids content as used for lumber mills (i.e., 83% solids).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe parameter values used for modeling methane emissions attributable to landfilled ash from panel plants were the same as those used for lumber mills.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eOther Wastes\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eStudies published by the Consortium for Research on Renewable Industrial Materials (CORRIM)\u003csup\u003e\u003csup\u003e[2]\u003c/sup\u003e\u003c/sup\u003e were used to develop a factor for estimating the amounts of non-ash solid waste landfilled at panel plants. The use of these reports to calculate waste quantities is described in Supplemental Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe DOC values in GHGRP Subpart TT are on a wet weight basis; therefore, the dry weights estimated herein were converted to wet weights using a solids content of 85% based on the fact that the Subpart TT DOC is taken from IPCC\u0026nbsp;\u003csup\u003e11\u003c/sup\u003e, in which the associated water content is 15%.\u003c/p\u003e\n\u003cp\u003eThe parameters for modeling \u0026ldquo;other\u0026rdquo; waste from panel plants were the same as used for lumber mills. \u0026nbsp; Details are provided in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePulp and Paper Mill Wastewaters\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWood product mills seldom produce wastewater. Most pulp and paper mills, however, do. In its 2022 annual inventory of GHG emissions and sinks, US EPA estimated 2020 GHG emissions from the treatment of pulp, paper, and paperboard mill wastewaters\u003csup\u003e32\u003c/sup\u003e. US EPA\u0026rsquo;s estimates are model-based and are subject to considerable uncertainty. Nonetheless, US EPA\u0026rsquo;s estimates are used as the basis for this updated inventory.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUS EPA estimates wastewater treatment emissions using IPCC models that calculate methane release based on information regarding the amount of organic matter subject to anaerobic conditions and factors that convert a fraction of this material into methane. US EPA also estimates nitrous oxide emissions associated with treating industry wastewater\u0026nbsp;\u003csup\u003e32\u003c/sup\u003e. To develop estimates for this profile, is it assumed that the most important parameter in US EPA\u0026rsquo;s calculations that changed significantly since 1990 was the amount of organic matter in untreated wastewater. Accordingly, estimates of 1990 and 2005 emissions were produced by scaling US EPA\u0026rsquo;s 2020 estimate based on influent loads. Data in NCASI 2019 indicate that influent loads decreased from about 25 kg BOD/metric ton production in 1990 to 15 kg/metric ton in 2020. Production data to convert these to mass loads were taken from US EPA\u0026nbsp;\u003csup\u003e24\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIt Is important to note that US EPA\u0026rsquo;s estimates for N\u003csub\u003e2\u003c/sub\u003eO emissions include emissions from wastewater treatment plants as well as emissions that occur in the environment attributable to the residual nitrogen in industry effluents.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTransport-Related Emissions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe forest products industry\u0026rsquo;s value chain requires transport of fibrous and nonfibrous raw materials, products, fuels, and wastes. This section contains calculations for the emissions associated with these transport operations except for the transport of fossil fuels used by manufacturing and converting operations (which is included in the factors used to calculate Scope 3 emissions for fuels earlier in this report). In the context of this report, these emissions are those associated with fossil fuel consumption by transport vehicles and are reported as Scope 3 whether the vehicles are owned by a forest products company or not.\u003c/p\u003e\n\u003cp\u003eThe estimates of transport-related emissions developed in this study rely heavily on data from the Census Bureau Commodity Flow Survey (CFS)\u003csup\u003e10\u003c/sup\u003e. Factors to consider when using CFS data are discussed in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eRoundwood Transport\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAlthough most of the transport-related calculations in this report are based on information from the CFS\u003csup\u003e10\u003c/sup\u003e, this is not possible for roundwood transport because the CFS does not cover the \u0026ldquo;forestry and logging\u0026rdquo; industry (additional information is available in Supplemental Information). Instead, emissions associated with roundwood transport are calculated using the assumptions and values shown in Table 8.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eProduct Transport\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eCFS data\u003csup\u003e10\u003c/sup\u003e are used in this report for estimating transport-related emissions for wood and paper products, both primary products and converted products. The products of interest to the US forest products are assigned SCTG codes 26, 27, 28, and 29. Detailed information on the CFS and its use in this report is available in Supplemental Information. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEmissions are calculated by multiplying the metric ton-km values from CFS reports by emission factors derived from multiple sources.The emission factors used for heavy-duty trucks are shown in Table 8. Emission factors for rail were obtained from the US Department of Transportation based on reported fuel efficiencies 332, 414, and 487 short ton-miles per gallon of fuel consumed in 1990, 2005, and 2020, respectively\u0026nbsp;\u003csup\u003e45\u003c/sup\u003e. Using emission factors for diesel fuel (see Table 8), these values can be converted to emission factors of 0.0211, 0.0169, and 0.0144 kg CO\u003csub\u003e2\u003c/sub\u003e per metric ton-km, respectively. Assuming that all transport of products was by truck or rail, these factors for trucking and rail transport were weighted (based on metric ton-km for each mode of transport)\u003csup\u003e10\u003c/sup\u003e to derive an overall emission factor for each commodity. \u0026nbsp;For SCTG codes 26 through 29, the ranges of weighted emission factors were 0.051 to 0.056 kg CO\u003csub\u003e2\u003c/sub\u003ee per metric ton-km in 1990 and 2005 and 0.045 to 0.051 kg CO\u003csub\u003e2\u003c/sub\u003ee per metric ton-km in 2020. SCTG code-specific values are shown in Supplementary Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 8.\u003c/strong\u003e Assumptions and Values Used to Calculate Roundwood Transport Emissions\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003eValue\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eSources\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eRoundwood transported (includes firewood)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003e1990, 445 million metric tons\u003c/p\u003e\n \u003cp\u003e2005, 408 million metric tons\u003c/p\u003e\n \u003cp\u003e2020, 376 million metric tons\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eFAOSTAT\u003csup\u003e16\u003c/sup\u003e, converted from cubic meters using a factor of 0.87 metric ton per cubic meter (from FAO 2020\u0026nbsp;\u003csup\u003e33\u003c/sup\u003e, Table 2.3.1, average of conifer and non-conifer)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eHaul mode\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003eDiesel truck\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eAssumed\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eHaul distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003e100 km one-way (round trip emissions assumed to be 1.75 times one-way emissions to account for empty return to the forest)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003e\u003csup\u003e34\u0026ndash;41\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eFuel economy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003e2.56 km/l (6.2 mpg) in 2020. Lower to 2.4 km/l for 2005 and 1990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eDavis and Boundy, 2022\u003csup\u003e42\u003c/sup\u003e, Table 2.16, converted using 129,000 Btu per gallon diesel\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eAverage load\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003e20 metric tons (22 short tons)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003e\u003csup\u003e39,40,40,43\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eDiesel emission factor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003e2.7 kg CO\u003csub\u003e2\u003c/sub\u003e/liter (10.21 kg CO\u003csub\u003e2\u003c/sub\u003e per gallon)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eUS EPA 2014\u003csup\u003e44\u003c/sup\u003e, CO\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eonly, does not include upstream emissions associated with fuel production\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eEmissions per km\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003e1.02 kg CO\u003csub\u003e2\u003c/sub\u003e/km in 2020, 1.12 kg CO\u003csub\u003e2\u003c/sub\u003e/km in 2005 and 1990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eCalculated\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eEmissions per metric ton-km based on 20 metric ton load and one-way haul distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 210px;\"\u003e\n \u003cp\u003e0.0512, 0.0562 and 0.0560 kg CO\u003csub\u003e2\u003c/sub\u003e per metric ton-km for 1990, 2005, and 2020 respectively\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eCalculated\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEmissions associated with transporting pellets were estimated separately because they are not included in the list of commodities in SCTG 26, wood products. Details are provided in Supplementary Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eCo-products Produced by Wood Products Mills\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eWood products mills produce significant quantities of chips, sawdust, etc. that are used as raw materials by other facilities. These materials, however, are included in the list of wood products in SCTG 26 and the emissions associated with their transport are therefore included in the total for wood products.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eNon-Fiber, Non-Fuel Inputs\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe production of forest products requires a range of inputs besides wood fiber. The production and transport of these materials result in GHG emissions. Emissions associated with the production of nonfiber, nonfuel inputs are estimated elsewhere in this report. In this section, transport-related emissions attributable to these inputs are examined.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eQuantities of non-fiber, non-fuel inputs were estimated from life cycle assessment (LCA) studies identified in Supplementary Information. Data from the CFS were used to identify appropriate transport distances, also described in Supplementary Information. All transport was assumed to be by truck with a cargo load of 20 metric tons, allowing the use of emission factors in Table 8.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eUsed Products\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAfter use, products are transported to recovery and/or disposal operations. Data on the quantities requiring transport were obtained from US EPA\u0026nbsp;\u003csup\u003e46\u003c/sup\u003e. The last value in the EPA data was for 2018, so this was used as the 2020 data point in this study. The haul distance used was 362 km (225 mi), the value reported for 2017 in the CFS for SCTG 4112\u003csup\u003e10\u003c/sup\u003e, waste and scrap of paper and paperboard. Trucks were assumed to be the mode of transport and the truck emission factors for 20 metric ton loads in Table 8 were used.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eEmissions from Products During Use\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFew forest products emit GHGs during use, or cause GHGs to be emitted during use. Forest-based fuels, however, release methane and nitrous oxide when burned, and these are included in Scope 3 inventories. Biogenic CO\u003csub\u003e2\u003c/sub\u003e emissions are not included as emissions because these flows to the atmosphere are captured in the production accounting used to calculate changes in biogenic carbon stocks, discussed earlier in this report. The GHG emissions released when biomass is used as fuel by industry are accounted for as direct emissions (discussed above). Emissions from use of non-industrial use of wood-based fuels are calculated separately using the following approach..\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eQuantities of wood-based fuels consumed domestically by non-industrial users were estimated from US Forest Service data\u003csup\u003e22\u003c/sup\u003e. Pellet exports, which are used primarily for electricity production, were calculated from data produced by the US Department of Agriculture Global Agricultural Trade System (GATS)\u003csup\u003e47\u003c/sup\u003e. European Integrated Pollution Prevention and Control Bureau (IPCC) emission factors\u0026nbsp;\u003csup\u003e11\u003c/sup\u003ewere used to estimate methane and nitrous oxide emissions from non-industrial use of wood-based fuels and production of electricity from wood-based fuels. Details are provided in Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eEnd-of-Life Emissions\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAt end-of-life, forest products are recycled, landfilled, combusted, or diverted to a beneficial use (e.g., composting). Emissions associated with recycling occur in transporting recovered fiber and using it to produce new products. These emissions are accounted for elsewhere in this study. End-of-life GHG emissions from combustion (primarily municipal solid waste [MSW] waste-to-energy) as well as GHG emissions from composting are small and not included here. See Supplementary Information for additional discussion of these emissions. The calculations in this report, therefore, are limited to GHG emissions from MSW landfills attributable to discarded forest products.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLandfill methane emissions attributable to forest products have been calculated as a fraction of total MSW landfill emissions reported in US EPA\u0026rsquo;s annual inventory\u003csup\u003e24\u003c/sup\u003e. To estimate the fraction of methane attributable to forest products, we separately modeled the decay of all decomposable fractions of MSW deposited in landfills since 1960. The data on deposits were taken from US EPA\u003csup\u003e46\u003c/sup\u003e. Parameter values for decay rates and nondegradable carbon were taken from the documentation for version 15 of US EPA\u0026rsquo;s Waste Reduction Model (WARM)\u003csup\u003e30\u003c/sup\u003e. The analysis of year-to-year decomposition and methane production is described in detail in Supplementary Information. Also discussed in Supplementary Information are factors that may affect the results of this approach.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe landfill emissions calculated here address only forest products disposed in MSW landfills. Considerable quantities of discarded wood products, however, are disposed of in dedicated construction and demolition (C\u0026amp;D) debris landfills. The amounts of methane produced by wood products in these landfills is expected to be small and therefore is not included in the estimates developed for this study. Additional discussion of C\u0026amp;D debris landfills can be found in Supplementary Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e[1] See CORRIM.org for more information.\u003c/p\u003e\n\u003cp\u003e[2] See CORRIM.org for more information.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch3\u003eDATA AVAILABILITY\u003c/h3\u003e\n\u003cp\u003eThe data used in this analysis is either contained or Supplementary Information or available via citations provided in Supplementary Information.\u003c/p\u003e\n\u003ch3\u003eADDITIONAL INFORMATION\u003c/h3\u003e\n\u003cp\u003eCompeting information statement: The authors declare no competing interests.\u003c/p\u003e\n\u003ch3\u003eFUNDING\u003c/h3\u003e\n\u003cp\u003e\u003cstrong\u003e\u003c/strong\u003eReid Miner received funding from NCASI to undertake this project.\u003c/p\u003e\n\u003ch3\u003eAUTHOR CONTRIBUTION STATEMENT\u003c/h3\u003e\n\u003cp\u003eReid Miner (corresponding author) performed much of the analysis and writing associated with carbon in forest products, emissions associated with producing and harvesting wood, upstream emissions associated with non-fiber, non-fuel inputs, converting emissions, transport emissions, emissions from the management of industry wastes, emissions from products use and end-of-life emissions.\u003c/p\u003e\n\u003cp\u003eDr. Barry Malmberg performed the calculations and prepared the material addressing Scope 1 combustion-related emissions and Scope 2 emissions. In addition, he participated in the calculation of converting emissions.\u003c/p\u003e\n\u003cp\u003eAdam Costanza prepared many the factors used to calculate Scope 3 life cycle emissions associated with non-fiber, non-fuel inputs, Scope 3 electricity-related emissions and transport-related emissions.\u003c/p\u003e\n\u003cp\u003eDr. Steve Prisley prepared the material describing impacts of forest ecosystem carbon.\u003c/p\u003e\n\u003ch3\u003eAUTHOR INFORMATION\u003c/h3\u003e\n\u003cp\u003e\u003cstrong\u003e*Corresponding Author\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNCASI, 1513 Walnut Street, Suite 200, Cary, NC, USA 27511\u003c/p\u003e\n\u003cp\u003ePhone (919) 600-1022\u003c/p\u003e\n\u003cp\u003eEmail: [email protected]\u003c/p\u003e\n\u003cp\u003eDr. Barry Malmberg\u003c/p\u003e\n\u003cp\u003eNCASI\u003c/p\u003e\n\u003cp\u003eemail: [email protected]\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAdam Costanza\u003c/p\u003e\n\u003cp\u003eNCASI\u003c/p\u003e\n\u003cp\u003eEmail: [email protected]\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDr. Steve Prisley\u003c/p\u003e\n\u003cp\u003ePrisley Forest Analytics LLC\u003c/p\u003e\n\u003cp\u003email: [email protected]\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eHeath, L. S. \u003cem\u003eet al.\u003c/em\u003e Greenhouse Gas and Carbon Profile of the U.S. Forest Products Industry Value Chain. \u003cem\u003eEnviron. Sci. Technol.\u003c/em\u003e \u003cstrong\u003e44\u003c/strong\u003e, 3999\u0026ndash;4005 (2010).\u003c/li\u003e\n \u003cli\u003eWBCSD \u0026amp; WRI. \u003cem\u003eGHG Protocol Corporate Accounting and Reporting Standard\u003c/em\u003e. https://ghgprotocol.org/corporate-standard (2004).\u003c/li\u003e\n \u003cli\u003eWBCSD \u0026amp; WRI. \u003cem\u003eCorporate Value Chain (Scope 3) Standard | GHG Protocol\u003c/em\u003e. https://ghgprotocol.org/corporate-value-chain-scope-3-standard (2011).\u003c/li\u003e\n \u003cli\u003eUnited States Environmental Protection Agency (EPA). \u003cem\u003eAnnexes to Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022\u003c/em\u003e. https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2022 (2024).\u003c/li\u003e\n \u003cli\u003eOswalt, S. N., Smith, W. B., Miles, P. D. \u0026amp; Pugh, S. A. Forest Resources of the United States, 2017: a technical document supporting the Forest Service 2020 RPA Assessment. \u003cem\u003eGen. Tech. Rep. WO-97. Washington, DC: U.S. Department of Agriculture, Forest Service, Washington Office.\u003c/em\u003e \u003cstrong\u003e97\u003c/strong\u003e, (2019).\u003c/li\u003e\n \u003cli\u003eKim, T., Wear, D., Coulston, J. \u0026amp; Li, R. Forest land use responses to wood product markets. \u003cem\u003eForest Policy and Economics\u003c/em\u003e \u003cstrong\u003e93\u003c/strong\u003e, 45\u0026ndash;52 (2018).\u003c/li\u003e\n \u003cli\u003eUnited States Environmental Protection Agency (EPA). Emissions \u0026amp; Generation Resource Integrated Database (eGRID). https://www.epa.gov/egrid (2020).\u003c/li\u003e\n \u003cli\u003eUnited States Environmental Protection Agency (EPA). \u003cem\u003eInventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022\u003c/em\u003e. https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2022 (2024).\u003c/li\u003e\n \u003cli\u003eAmerican Forest and Paper Association (AF\u0026amp;PA). \u003cem\u003e2020 Statistics, Paper, Paperboard \u0026amp; Pulp\u003c/em\u003e. (2021).\u003c/li\u003e\n \u003cli\u003eUnited States Census Bureau. Commodity Flow Survey Tables. \u003cem\u003eCensus.gov\u003c/em\u003e https://www.census.gov/programs-surveys/cfs/data/tables.html (2025).\u003c/li\u003e\n \u003cli\u003eIPCC (Intergovernmental Panel on Climate Change). \u003cem\u003e2006 IPCC Guidelines for National Greenhouse Gas Inventories\u003c/em\u003e. https://www.ipcc-nggip.iges.or.jp/public/2006gl/index.html (2006).\u003c/li\u003e\n \u003cli\u003eIPCC (Intergovernmental Panel on Climate Change). \u003cem\u003eClimate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change\u003c/em\u003e. https://www.ipcc.ch/report/ar5/wg1/ (2013).\u003c/li\u003e\n \u003cli\u003eWBCSD \u0026amp; WRI. GHG Protocol Calculation Tools and Guidance. https://ghgprotocol.org/calculation-tools-and-guidance?ap3c=IGXmCH6WDeDPomoEAGXmCH6mIt-Db9NCNH00dmje0ZqebCmgPw#sector_specific_tools_id (2009).\u003c/li\u003e\n \u003cli\u003eUnited States Energy Information Administration (EIA). Manufacturing Energy Consumption Survey (MECS). https://www.eia.gov/consumption/manufacturing/.\u003c/li\u003e\n \u003cli\u003eUnited States Environmental Protection Agency (USEPA). Greenhouse Gas Reporting Program (GHGRP). https://www.epa.gov/ghgreporting (2014).\u003c/li\u003e\n \u003cli\u003eUnited Nations Food and Agriculture Organization (FAO). FAOSTAT. https://www.fao.org/faostat/en/#home.\u003c/li\u003e\n \u003cli\u003eNCASI. Scope 3 GHG Screening Tool, version 1.1a. NCASI (2025).\u003c/li\u003e\n \u003cli\u003eNational Renewable Energy Laboratory (NREL). \u003cem\u003eLife Cycle Greenhouse Gas Emissions from Electricity Generation: Update\u003c/em\u003e. (2021).\u003c/li\u003e\n \u003cli\u003eWhitaker, M., Heath, G. A., O\u0026rsquo;Donoughue, P. \u0026amp; Vorum, M. Life Cycle Greenhouse Gas Emissions of Coal-Fired Electricity Generation. \u003cem\u003eJournal of Industrial Ecology\u003c/em\u003e \u003cstrong\u003e16\u003c/strong\u003e, S53\u0026ndash;S72 (2012).\u003c/li\u003e\n \u003cli\u003eNCASI \u0026amp; International Finance Corporation of the World Bank (IFC). Forest Industry Carbon Assessment Tool (FICAT). NCASI (2025).\u003c/li\u003e\n \u003cli\u003eAmerican Forest and Paper Association (AF\u0026amp;PA). \u003cem\u003e2019 Statistics, Paper, Paperboard \u0026amp; Pulp\u003c/em\u003e. (2020).\u003c/li\u003e\n \u003cli\u003eHoward, J. L. \u0026amp; Liang, S. U.S. timber production, trade, consumption, and price statistics, 1965-2017. Forest Service Research Data Archive https://doi.org/10.2737/RDS-2018-0035 (2019).\u003c/li\u003e\n \u003cli\u003eNCASI. \u003cem\u003eUnpublished Survey Data on Solid Waste Generation Rates\u003c/em\u003e. (2025).\u003c/li\u003e\n \u003cli\u003eUnited States Environmental Protection Agency (EPA). \u003cem\u003eAnnexes to Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020\u003c/em\u003e. https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2020 (2022).\u003c/li\u003e\n \u003cli\u003eCampbell, A. Recycling and disposing of wood ash, TAPPI JOURNAL, September 1990, Vol. 73(9). \u003cem\u003eTAPPI Journal\u003c/em\u003e \u003cstrong\u003e73\u003c/strong\u003e, 141\u0026ndash;146 (1990).\u003c/li\u003e\n \u003cli\u003eNCASI. \u003cem\u003eA Summary of Available Data on the Chemical Composition of Forest Products Industry Solid Wastes\u003c/em\u003e. (1999).\u003c/li\u003e\n \u003cli\u003eMalyan, S. K. \u003cem\u003eet al.\u003c/em\u003e Methane production, oxidation and mitigation: A mechanistic understanding and comprehensive evaluation of influencing factors. \u003cem\u003eScience of The Total Environment\u003c/em\u003e \u003cstrong\u003e572\u003c/strong\u003e, 874\u0026ndash;896 (2016).\u003c/li\u003e\n \u003cli\u003eNCASI. \u003cem\u003eSolid Waste Management and Disposal Practices in the US Paper Industry\u0026minus;1995\u003c/em\u003e. (1999).\u003c/li\u003e\n \u003cli\u003eNCASI. \u003cem\u003eSolid Residual Generation and Beneficial Use, and Wastewater Treatment Performance and Practices of the North American Pulp and Paper Industry\u003c/em\u003e. (2019).\u003c/li\u003e\n \u003cli\u003eUnited States Environmental Protection Agency (EPA). \u003cem\u003eDocumentation for Greenhouse Gas Emission and Energy Factors Used in the Waste Reduction Model (WARM) - Management Practices Chapters\u003c/em\u003e. https://www.epa.gov/sites/default/files/2020-12/documents/warm_management_practices_v15_10-29-2020.pdf (2020).\u003c/li\u003e\n \u003cli\u003eWang, X., Padgett, J. M., De la Cruz, F. B. \u0026amp; Barlaz, M. A. Wood Biodegradation in Laboratory-Scale Landfills. \u003cem\u003eEnviron. Sci. Technol.\u003c/em\u003e \u003cstrong\u003e45\u003c/strong\u003e, 6864\u0026ndash;6871 (2011).\u003c/li\u003e\n \u003cli\u003eUnited States Environmental Protection Agency (EPA). \u003cem\u003eInventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020\u003c/em\u003e. https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2020 (2022).\u003c/li\u003e\n \u003cli\u003eUnited Nations Food and Agriculture Organization (FAO), I. and U. N. \u003cem\u003eForest Product Conversion Factors\u003c/em\u003e. (FAO, ITTO and United Nations ;, 2020).\u003c/li\u003e\n \u003cli\u003eMilota, M., Science, W. \u0026amp; Hall, R. \u003cem\u003eLife Cycle Assessment for the Production of Southeastern Softwood Lumber\u003c/em\u003e. (2020).\u003c/li\u003e\n \u003cli\u003eMilota, M., Science, W. \u0026amp; Hall, R. \u003cem\u003eLife Cycle Assessment for the Production of Pacific Northwest Softwood Lumber\u003c/em\u003e. https://corrim.org/wp-content/uploads/2020/06/CORRIM-AWC-PNW-Lumber.pdf (2020).\u003c/li\u003e\n \u003cli\u003eOneil, E. \u0026amp; Puettmann, M. E. A Life-Cycle Assessment of Forest Resources of the Pacific Northwest, USA*. https://doi.org/10.13073/FPJ-D-17-00011 (2017) doi:10.13073/FPJ-D-17-00011.\u003c/li\u003e\n \u003cli\u003ePuettmann, M., Kaestner, D. \u0026amp; Taylor, A. \u003cem\u003eLife Cycle Assessment for the Production of Southeast Softwood Plywood\u003c/em\u003e. (2020).\u003c/li\u003e\n \u003cli\u003eBergman, R. D. \u0026amp; Bowe, S. A. Life-Cycle Inventory of Hardwood Lumber Manufacturing in the Northeast and North Central United States.\u003c/li\u003e\n \u003cli\u003eBarrett, S., Bolding, C. \u0026amp; Munsell, J. Characteristics of Logging Businesses across Virginia\u0026rsquo;s Diverse Physiographic Regions. \u003cem\u003eForests\u003c/em\u003e \u003cstrong\u003e8\u003c/strong\u003e, 468 (2017).\u003c/li\u003e\n \u003cli\u003eConrad, J., Greene, W. \u0026amp; Hiesl, P. The Evolution of Logging Businesses in Georgia 1987\u0026ndash;2017 and South Carolina 2012\u0026ndash;2017. \u003cem\u003eForest Science\u003c/em\u003e \u003cstrong\u003e64\u003c/strong\u003e, (2018).\u003c/li\u003e\n \u003cli\u003eConrad, J. L. Log truck insurance premiums, claims, and safety practices among logging businesses in the US South. \u003cem\u003eInternational Journal of Forest Engineering\u003c/em\u003e \u003cstrong\u003e34\u003c/strong\u003e, 204\u0026ndash;215 (2023).\u003c/li\u003e\n \u003cli\u003eDavis, S. C. \u0026amp; Boundy, R. G. Transportation Energy Data Book: Edition 40. (2022).\u003c/li\u003e\n \u003cli\u003eConrad, J. L. Evaluating Profitability of Individual Timber Deliveries in the US South. \u003cem\u003eForests\u003c/em\u003e \u003cstrong\u003e12\u003c/strong\u003e, 437 (2021).\u003c/li\u003e\n \u003cli\u003eUnited States Environmental Protection Agency (EPA). Emission Factors for Greenhouse Gas Inventories. (2014).\u003c/li\u003e\n \u003cli\u003eUnited States Department of Transportation (US DOT). Class I Rail Freight Fuel Consumption and Travel. \u003cem\u003eClass I Rail Freight Fuel Consumption and Travel\u003c/em\u003e https://www.bts.gov/content/class-i-rail-freight-fuel-consumption-and-travel (2025).\u003c/li\u003e\n \u003cli\u003eUnited States Environmental Protection Agency (EPA). \u003cem\u003eAdvancing Sustainable Materials Management: 2018 Tables and Figures\u003c/em\u003e. https://www.epa.gov/sites/default/files/2021-01/documents/2018_tables_and_figures_dec_2020_fnl_508.pdf (2020).\u003c/li\u003e\n \u003cli\u003eUnited States Department of Agriculture (USDA). FAS - Global Agricultural Trade System (GATS). https://apps.fas.usda.gov/gats/default.aspx.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Forest Products, Forest Carbon, Carbon Footprint, Wood Products, Pulp and Paper, Life Cycle Assessment ","lastPublishedDoi":"10.21203/rs.3.rs-8290322/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8290322/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"This study presents detailed greenhouse gas (GHG) emissions and carbon profiles of the US forest products industry value chain in 1990, 2005 and 2020. Gross emissions were 291, 268 and 172 million metric tons CO2e in 1990, 2005 and 2020, respectively. Between 1990 and 2020, GHG emissions from fuel consumption were reduced by 44%, attributable primarily to fuel switching. Over this period, the greening of the grid resulted in a 43% reduction in emissions attributable to purchased electricity while increased recycling and improved landfill gas control reduced product end-of-life emissions by 61%. These three sources accounted for 64% of gross value chain emissions in 2020 and 93% of the reductions from 1990 to 2020. Forest carbon stocks were stable or increasing on land supplying wood to the industry while stocks of carbon stored in forest products increased by 124 and 97 million metric tons CO2e per year in 1990 and 2020, respectively. Continued progress in reducing value chain emissions will require maintaining stable carbon stocks on wood-supplying land, continued reductions in GHGs associated with purchased fuels and electricity and continued progress in keeping used forest products out of landfills and capturing landfill methane.","manuscriptTitle":"Greenhouse Gas and Carbon Profile of the US Forest Products Industry: 1990 to 2020","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-26 13:34:18","doi":"10.21203/rs.3.rs-8290322/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-02-02T10:35:55+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-30T21:58:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"7960196478474247997878530579048008990","date":"2026-01-20T07:16:24+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-13T09:36:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"26087775860577727562551353455784869403","date":"2026-01-08T10:13:56+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"7960196478474247997878530579048008990","date":"2026-01-05T11:52:10+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-02T21:47:03+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-02T07:28:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"25409450104132617866730828715101808852","date":"2026-01-01T16:13:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"247498085605310461070143233932453096293","date":"2025-12-31T07:08:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"86259145141308131698702856448676733189","date":"2025-12-30T21:32:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"31552897967691324256530428694213531776","date":"2025-12-24T10:29:51+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-24T10:18:20+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-12-19T04:40:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-12-09T05:13:42+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-12-09T05:11:42+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-12-05T18:44:35+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"271c656d-67bd-476a-8e86-6cdb9dc518cb","owner":[],"postedDate":"December 26th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":60205939,"name":"Earth and environmental sciences/Climate sciences"},{"id":60205940,"name":"Earth and environmental sciences/Environmental sciences"},{"id":60205941,"name":"Earth and environmental sciences/Environmental social sciences"}],"tags":[],"updatedAt":"2026-02-12T19:08:46+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-26 13:34:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8290322","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8290322","identity":"rs-8290322","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}