Resolving the land carbon accounting riddle: consistent metrics for countries and products

Resolving the land carbon accounting riddle: consistent metrics for countries and products | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Method Article Resolving the land carbon accounting riddle: consistent metrics for countries and products Miguel Brandão This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6874858/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Historically, land-use change has contributed to approximately one-third of anthropogenic carbon dioxide (CO2) emissions, demonstrating the critical role land use can play in rebalancing the global carbon cycle. However, the continued occupation of land by human activities delays the regeneration of potential carbon stocks in terrestrial ecosystems – a dynamic largely overlooked that remains underrepresented in climate accounting, despite the widespread use of Global Warming Potentials (GWPs). Inconsistencies in the application of GWPs further challenge the accurate assessment of land-use impacts. This study introduces a new metric – GWPland – for product-level carbon footprinting and life cycle assessment (LCA), which uses differentiated impulse response functions (IRFs) to represent the delayed carbon regeneration resulting from land occupation. By computing land use IRFs, we can calculate Absolute Global Warming Potentials (AGWPs) for various occupation and regeneration periods, thus enabling the derivation of GWPland factors over 20-, 100- and 500-year horizons. GWPland increases non-linearly with occupation duration and approach 1 when the occupation time exceeds the GWP horizon or regeneration is indefinitely delayed. At the country level, we propose three adjusted GWP metrics – GWPALS (all land sinks), GWPPLS (partial land sinks), and GWPNLS (no land sinks) – to improve consistency with national greenhouse gas inventory (NGHGI) reporting. These variants reduce default (IPCC AR6) non-CO2 GWP values by up to 13% (GWPPLS) and 21% (GWPNLS), helping to avoid double-counting of the terrestrial sink. Depending on land sink treatment, reported national emissions can shift significantly, with GWPNLS potentially resulting in net-negative totals for countries like Brazil. Together, these metrics enhance consistency across climate accounting frameworks, enabling more accurate integration of land-use dynamics into carbon footprinting, LCAs, national reporting, and climate policy. Climate Analysis and Modeling Land use land-use change forestry LULUCF carbon neutrality CO2 accounting GWP LCA managed land proxy NGHGI DGVMs Full Text Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6874858","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Method Article","associatedPublications":[],"authors":[{"id":470012287,"identity":"ffae0b81-2e84-4317-86a1-9cab8d066dd6","order_by":0,"name":"Miguel Brandão","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAt0lEQVRIiWNgGAWjYDACZhBRcEBOgoGHJC0GB4wl2IjWwgDRkjiDaC267ezXJD4Y3EmfOb/3AOOPCiK0mB3mKZOcYfAsdzYbXwIzzxnitKRJ8xgczp3HxmPAzNhGrJY/BofT5YBaGH/+I0oL+zFpBoPDCdJALQy8DcTZwmzZY/DMcGZbjsFhnmPEaDl//OGNHxV35CUOnzF8+KOGCC0MDED3wMABojQwMLA/IFLhKBgFo2AUjFgAADbBM25Jc4MQAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-8101-8928","institution":"KTH Royal Institute of Technology","correspondingAuthor":true,"prefix":"","firstName":"Miguel","middleName":"","lastName":"Brandão","suffix":""}],"badges":[],"createdAt":"2025-06-11 21:06:25","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-6874858/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6874858/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":84537381,"identity":"c60cde52-abfd-49b9-9b16-f3472440cf60","added_by":"auto","created_at":"2025-06-13 07:25:47","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1399471,"visible":true,"origin":"","legend":"","description":"","filename":"SubmissiontoERL.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6874858/v1_covered_540afb2f-1d12-4cd7-a7ca-c2956250d7a5.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cem\u003eResolving the land carbon accounting riddle: consistent metrics for countries and products\u003c/em\u003e\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Land use, land-use change, forestry, LULUCF, carbon neutrality, CO2 accounting, GWP, LCA, managed land proxy, NGHGI, DGVMs","lastPublishedDoi":"10.21203/rs.3.rs-6874858/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6874858/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cem\u003eHistorically, land-use change has contributed to approximately one-third of anthropogenic carbon dioxide (CO2) emissions, demonstrating the critical role land use can play in rebalancing the global carbon cycle. However, the continued occupation of land by human activities delays the regeneration of potential carbon stocks in terrestrial ecosystems – a dynamic largely overlooked that remains underrepresented in climate accounting, despite the widespread use of Global Warming Potentials (GWPs). Inconsistencies in the application of GWPs further challenge the accurate assessment of land-use impacts.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThis study introduces a new metric – GWPland – for product-level carbon footprinting and life cycle assessment (LCA), which uses differentiated impulse response functions (IRFs) to represent the delayed carbon regeneration resulting from land occupation. By computing land use IRFs, we can calculate Absolute Global Warming Potentials (AGWPs) for various occupation and regeneration periods, thus enabling the derivation of GWPland factors over 20-, 100- and 500-year horizons.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eGWPland increases non-linearly with occupation duration and approach 1 when the occupation time exceeds the GWP horizon or regeneration is indefinitely delayed. At the country level, we propose three adjusted GWP metrics – GWPALS (all land sinks), GWPPLS (partial land sinks), and GWPNLS (no land sinks) – to improve consistency with national greenhouse gas inventory (NGHGI) reporting. These variants reduce default (IPCC AR6) non-CO2 GWP values by up to 13% (GWPPLS) and 21% (GWPNLS), helping to avoid double-counting of the terrestrial sink. Depending on land sink treatment, reported national emissions can shift significantly, with GWPNLS potentially resulting in net-negative totals for countries like Brazil. 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