Divergent impacts of ocean tipping and global warming on habitability

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This is based on eventual net effects on country-level mean annual temperature 5,6 , with no consideration of effects on precipitation, spatial detail, or shifting directions of climate change. Here, we explore the impacts of consecutive climate shifts on the human climate niche 7,8 – first 2.5°C global warming, disproportionately affecting the Global South, and then a collapse of the AMOC, impacting North Atlantic adjacent landmasses the most. We show that these sequential changes have very different spatial patterns of precipitation and temperature effects, some of which offset each other, while others are compounding. This represents a first step towards a more nuanced, spatially and temporally explicit approach to the quantification of the impacts of tipping a critical component of the climate system. Earth and environmental sciences/Climate sciences Earth and environmental sciences/Climate sciences/Climate change/Climate and Earth system modelling Earth and environmental sciences/Climate sciences/Climate change/Climate-change impacts tipping point climate niche displacement adaptation Figures Figure 1 Figure 2 Figure 3 Figure 4 Main The Atlantic Meridional Overturning Circulation (AMOC) - part of the global ocean thermohaline circulation - plays a crucial role in the circulation patterns that influence global temperature and precipitation. While there is uncertainty 9,10 , some observational evidence suggests that the AMOC has weakened by around 15 percent in recent decades, is at its weakest point in the last 1,600 years and that this weakening may be accelerating 11–14 . Ongoing freshwater influx in the North Atlantic may inhibit deep water formation resulting in a continuing weakening - or even collapse - of the AMOC 15–17 . This would represent a fundamental reorganization of ocean circulation, causing a redistribution of heat around the planet and a corresponding coupled response from the atmosphere 18 . The IPCC consensus is that while the AMOC will “very likely” (90-100%) weaken later this century, it is “very unlikely” (<10%) to collapse within this century 19 . However, others consider the risk of AMOC collapse to become significant between 2-3°C global warming 16,20,21 . Recent research estimated that AMOC is on course to collapse 22 and this could occur between 2025 and 2095, with a central estimate of 2050, if global carbon emissions are not reduced 20 . Here we assess the impacts of a collapse of the AMOC at 2-3°C global warming above pre-industrial temperature. A world in which the global mean temperature is 2.5°C warmer than pre-industrial times is representative of where we will end up later this century under current legally-binding policies 23 . Crossing an AMOC tipping point would have major global ramifications. These include a drastic cooling of western Europe, a reduction of rainfall in the Atlantic region and a shift in the intertropical convergence zone shifting rainfall southwards. The change in ocean circulation patterns would affect marine ecosystems and give faster sea level rise along the Northeast seaboard of North America and parts of Europe. Stronger hurricanes in the Southeastern United States and the Caribbean, and reduced rainfall across the Sahel have also been predicted 1,24–27 . It could also trigger tipping points in the Amazon and have significant impacts on tropical monsoon systems 28–32 . Recent work indicates that, without the AMOC, the tropical Pacific Ocean cools, and trade winds intensify and shift south, putting the Earth in a climate state that resembles a permanent La Niña, which could trigger catastrophic monsoons and flooding in the South Pacific 33 . An AMOC collapse may thus represent an existential threat to humanity 34 . Some economic analyses have hypothesized that AMOC collapse would cause a 25-30% loss to GDP comparable with the Great Depression but irreversible 35 . However, other economic analyses have suggested that despite the possibility of wide-reaching economic and human impacts, the impact on GDP may be small or even positive 2–4 . A key weakness across these studies, which rely on simple Integrated Assessment Models (IAMs), is the overlooking of precipitation changes and within-country climate variations in favor of a narrow focus on temperature impacts on GDP. This fails to account for substantially different climate change effects in subregions. Further, this approach does not account for the impacts of potentially divergent directions of climate change due to diverse processes. There are many recognised problems with simple integrated assessment model representation of the impacts of climate change and especially tipping points 5,36–40 . Most fundamentally, they tend to conflate weather variability with long-term climate changes 5,41 and apply spatial analogues across different geographic and temporal scales. This false equivalence ignores the fact that climate change involves systematic shifts in baseline weather patterns over multi-decadal time spans, with profound economic implications relating to infrastructure, supply chains, and more. Much of the existing work often assumes that human economies are highly adaptable to climate change, implying minimal economic impacts, but this method does not fully account for the possibility of large-scale, nonlinear changes like tipping points, and the potential for successive climate regime shifts in different directions may challenge the presumption of high adaptability, testing the limits of social and economic resilience even with humanity's capacity to adjust. As an alternative to the use of IAMs, the human climate niche 7 takes an ecological approach to quantify how human population density depends on mean annual temperature (MAT) and mean annual precipitation (MAP). This concept, analogous to the ecological niche occupied by a species 42 , has been used to characterize the climatic conditions suitable for human societies 7,8 . The niche is found to be conserved over centuries 8 , with similar relationships between climate and human population density, crop yields, livestock distributions, and economic productivity observed across different historical periods. As such, the climate niche provides a simple, integrated way of starting to consider the impacts of temperature and precipitation on human habitability. However it does not capture the impact of sea level rise and lacks explicit representation of the effects of seasonality or extremes. We examine the impacts of 2.5°C global warming and AMOC collapse independently and then in combination. We show how these successive large-scale shifts in global climate conditions in conflicting directions would challenge humanity's capacity to adapt in many regions. Projected Change Our study examines HadGEM3-GC2 model scenarios portraying the impacts of 2.5°C global warming under SSP1-2.6, isolated AMOC collapse, and AMOC collapse following 2.5°C global warming. The latter scenario is produced by a linear combination of the previous ones and as such misses some key non-linear effects. For instance, the simulated cooling in high northern latitudes will be overstated due to more strongly amplified sea-ice growth in the control climate than in a warmer world where much ice has been lost. The scenario of AMOC collapse alone remains theoretical, requiring additional warming or freshwater forcing for a full collapse. Our previous work considered the 2015 population distribution under the 1960–1990 mean climate as a baseline 8 and the 1980 population distribution under the 1960–1990 mean climate as the reference state 7 . Here our analysis of changes in the human climate niche is based on deviations from a control scenario representative of the 1990-2020 climatological mean and uses the 2020 population. The 1990-2020 mean better represents recent climatological conditions that human systems are adapted to and is more relevant for assessing deviations caused by an AMOC collapse that may occur in the upcoming decades. Under SSP1-2.6, our model projects a 2.5°C warming by the end of the century. As shown by Xu et al. (2020) 8 and Lenton et al. (2023) 7 this warming will disproportionately impact the tropics. The projected geographical shift of favorable MAT-MAP conditions over the rest of the century is substantial, with optimal conditions for humans projected to move poleward and with the worst effects in the tropics and some extra-tropical regions (Figure 1A). While AMOC collapse in isolation remains a hypothetical scenario, it provides valuable insights into the isolated impacts of this tipping point. Our simulations show that AMOC collapse would cause striking geographical shifts in the human climate niche (Figure 1B), disproportionately affecting the Northern Hemisphere, particularly Europe. In these simulations, Europe and higher northern latitudes experience significant cooling of up to 8°C, while the Southern Hemisphere experiences little to no warming (Figure S1A). Furthermore, most of the Northern Hemisphere experiences drying, except for North America, which becomes slightly wetter on average (Figure S1B). Notably, there are disruptions to the Indian summer monsoon and significant drying in the Amazon basin, highlighting potential cascading effects. On a global scale, regions in the tropics and south of the equator become more habitable on average, while habitability decreases in the Global North, particularly in higher latitudes (Figure 1B). Sub-Saharan Africa, as well as Central and South America, see the largest gain in habitability. In the combined scenario of 2.5°C global warming followed by AMOC collapse (Figure 1C), the average change in population-weighted human experienced temperature is +0.7°C. This scenario exhibits contrasting temperature responses between higher northern latitudes and the tropics and Southern Hemisphere (Figure S1A). Precipitation patterns also differ, with reduced precipitation in the Northern Hemisphere and increased precipitation in the Southern Hemisphere. Europe emerges as the most negatively impacted region, experiencing both cooling and reduced precipitation. North America becomes mostly more suitable due to a negligible change in temperature from the combined effects of 2.5°C and AMOC collapse, accompanied by a general increase in precipitation. Large swaths of South America, particularly Brazil, become less suitable due to amplification of two factors under the combined 2.5°C warming and AMOC collapse scenario - a reduction in precipitation and increase in temperature making the region hotter and dryer. Relative to the warming only scenario, suitability in most of sub-saharan Africa increases due to increases in rainfall, while equatorial Africa and Northern Africa - where the impact is dominated by the temperature increase in the warming scenario - see a marked decrease in suitability. Serial Shifts Our analysis shows that while a 2.5°C global warming leads to widespread temperature increases across both hemispheres, the shutdown of the AMOC triggers divergent temperature responses (Figure S1A). Initially, extratropical latitudes in the Northern Hemisphere warm, followed by widespread cooling due to AMOC shutdown. In contrast, the tropics and the Southern Hemisphere experience widespread warming. These serial shifts in the climate niche highlight the complexity of the impacts, especially in regions like the Northern Hemisphere extratropics, where opposing temperature changes occur. While a few regions may experience amplified effects of AMOC collapse on the human climate niche compared to warming alone (Figure 2), overall, AMOC collapse predominantly shifts the climate niche in the opposite direction of warming. This means that where warming has a positive impact on the MAT-MAP niche, AMOC collapse will have a negative impact, and vice versa. While some regions like northern Europe exhibit amplified cooling under the combined scenario compared to AMOC collapse alone, the predominant pattern is one of divergence rather than amplification of effects. For instance, parts of Canada experience warming of 2-4°C under 2.5°C, but this is almost entirely negated by the 2-6°C cooling from an AMOC collapse. This realignment of temperature regimes from one extreme to the other within a relatively short period poses significant challenges for adaptation. The serial reversals are even starker when examining the spatial context of precipitation changes. The US Southwest is projected to experience over 20% drying under 2.5°C warming, potentially straining water resources. However, an AMOC collapse could increase rainfall by 10-20% in this region, rendering any incremental adaptations for drought conditions maladaptive. Globally, changes in suitability are compounding for 27% of the global population, while changes in suitability oppose each other for 73% of population. Human Exposure To illustrate climatic shifts and human exposure changes, we analyze the MAP-MAT niche relative to the 2020 population distribution 43 (Figure S3). Under a scenario of 2.5°C global warming combined with AMOC collapse (Figure S3A), reduced precipitation decreases suitability in densely populated regions like western Europe, eastern North America, the Amazon, and western Africa (Figure 3). Conversely, suitability increases in less populated regions like southern Africa, parts of South America, and south Asia. Similar trends occur with MAT changes (Figure S3B), showing suitability increases in sparsely inhabited higher latitudes but decreases in densely populated temperate and tropical zones. Overlaying niche shifts with population maps reveals significant human exposures to declining suitability conditions in major population clusters, such as urban zones in Southeast Asia and India, due to the compounding impacts of warming and AMOC collapse. Projections of climate niche shifts under a global warming followed by AMOC collapse scenario unveil winners and losers (Figure 4). Under 2.5°C global warming alone, the tropics and Southern Hemisphere face substantial declines in suitability compared to higher northern latitudes. In a combined scenario, countries across all regions experience both increases (Figure 4A) and decreases (Figure 4B) in suitability, with Europe emerging as a significant loser. Some countries, like Zimbabwe and Botswana, experience compounding gains initially due to favorable shifts following prior warming, reinforced by AMOC collapse. However, this may be short-lived if subsequent warming exceeds habitability thresholds, particularly affecting regions in the Global South. Discussion and conclusions Previous research indicates that the tropics may face greater climate impact burdens compared to the extratropical regions in the Northern Hemisphere as temperatures surpass optimal human conditions in more areas 44 . Here we show an AMOC collapse could alter this picture, causing large shifts in climate suitability elsewhere, especially in Europe, and altering the direction of change in climate suitability in many regions. This poses a major adaptation challenge, as regions adapting to one trend in conditions may abruptly face a reversal, stressing natural and human adaptive capacities and potentially rendering some adaptations maladaptive 45 , 46 . For example, poleward migration of agricultural production in Europe (as is already observed) 47 would become extremely maladaptive after a tipping point of AMOC collapse. Similarly in the Southern States of the US, declining climate suitability would be abruptly reversed. The exact numerical values will depend on the specific model and scenario assumptions, but the general patterns of temperature and precipitation impacts are expected to be robust because similar patterns of change are seen for forced AMOC collapse simulations across different general circulation models (GCMs) 48 – 50 . Some nations like the United Kingdom, Netherlands, and Spain emerge as acute "losers," with climate conditions becoming substantially less suitable due to the cooling and drying effects of AMOC collapse compounding the initial warming impacts. Conversely, parts of southern Africa and South America experience increases in suitability as AMOC changes offset some of the detrimental warming effects in those regions. However, these conditions may prove short-lived and could lead to maladaptation if temperatures subsequently exceed human habitability thresholds due to continued warming 51 . The tropics merit particular attention given their vulnerability to climate change highlighted in the introduction. While some tropical regions like parts of South America face warming further compounded by drying from AMOC impacts, the core tropical regions experience a more mixed signal. Offsetting effects which may appear beneficial in the near-term, like rainfall increases counteracting warming, could ultimately prove transient if temperatures continue rising past human habitability thresholds. These complexities underscore the need for granular, systems-based risk assessments accounting for interactions across sectors and scales. There are some important limitations to our approach of using annual mean temperature and precipitation changes. Large seasonal changes in precipitation are seen locally in the tropics with an AMOC collapse, and this pronounced seasonality could have important impacts on agricultural crops and other sectors that are missed by looking at annual means. Extremes are also not captured by this approach, which could lead to underestimating some of the impacts. Overlay maps of projected climate niche shifts with current population distributions reveal substantial human exposure clusters facing declining habitability conditions. This includes urban centers across Southeast Asia, India, and parts of coastal West Africa, primarily driven by the compounding temperature increases under the combined warming and AMOC collapse scenario. However, the spatial redistribution also suggests potential migration corridors tracking niche shifts, both poleward in the northern hemisphere but also into regions made wetter by AMOC precipitation pattern changes. Quantifying these exposure hotspots and emergent population redistribution risks is critical for prioritizing adaptation efforts and infrastructure resilience investments. It is important to note that our approach of using annual mean temperature and precipitation changes has some key limitations in capturing the full impacts. Specifically, it misses large seasonal variations as well as changes in extremes that could have very significant effects. For example, large seasonal changes in precipitation are projected in the tropics with an AMOC collapse, which could have major impacts on agricultural crops and other sectors. Additionally, an increase in extreme winter storms has been linked to AMOC collapse in regions like the UK, which is not reflected in the annual mean changes. These examples highlight that while our approach provides a reasonable first-order approximation, future work should include more comprehensive assessments that resolve seasonal cycles and extreme events. While the responses in models forced by different forcings are generally additive, the approach of linearly combining the isolated warming and AMOC collapse scenarios does not account for non-linear feedbacks and interactions that would occur when compounding such major climate system perturbations 52 . Therefore, caution is warranted regarding the exact magnitudes projected. Notably, the Arctic cooling is overestimated when AMOC collapse happens from a warmed baseline since the ice-albedo feedback would be dampened when ice loss has already occurred under warming 53 – 55 . Since the warming scenario used already included some AMOC weakening, this linear recombination deviates from the assumption of separable effects. This may lead to an overestimation of the magnitudes of changes, such as European cooling, which would be tempered by residual warming and the lack of accounting for non-linear feedbacks and interactions. Additionally, linearly adding the AMOC's reorganization of tropical precipitation patterns to the global warming drying trend may obscure or distort the actual precipitation shift in the tropics. The adaptation literature highlights the challenges societies face in keeping pace with gradual climate changes 56 . If climate change itself adds to adaptation constraints and limits, then abrupt changes and reversals will prove to be even more disruptive, potentially overwhelming existing coping mechanisms, making long-term planning extremely difficult, and pushing us to the social limits for adaptation to climate change 57 . Any successful adaptations to the initial climate trend may become maladaptive. While a reasonable first order approximation of the impact of global warming 8 , the use of annual mean temperature and precipitation to define the "human climate niche" simplifies complex impacts in regions with large seasonal cycles or extreme events, which would further stress adaptive capacity 58 – 60 . Our results illustrate that simplistic assumptions about the geographic distribution of climate impacts and adaptation needs in many economic models may miss critically important aspects. An AMOC collapse could produce successive, opposing climate shifts in some regions, challenging assumptions of gradual adaptation built into models evaluating damages solely through temperature impacts on national GDP growth. Instead of the current approach, systemic risk assessment that accounts for potential non-linear, spatially heterogeneous impacts is necessary to evaluate serial climate shifts and develop robust adaptation strategies 61 . To better assess tipping risks, economic models should move beyond linking nationally-averaged temperature changes to GDP impacts. Representing potential for abrupt, heterogeneous changes across regions is important, rather than assuming globally well-mixed conditions. While challenging, capturing these complex dynamics is crucial for developing adequate climate risk management strategies. Despite simplifications, this analysis provides an integrated perspective on potential disruptive climate interactions, motivating further research to better constrain magnitudes and represent relevant feedbacks. We highlight the potential for profoundly uneven human impacts from an AMOC collapse triggered by global warming.The possibility of undergoing successive large-scale climate regime shifts in alternating directions presents an unprecedented challenge that requires rethinking how we model and evaluate climate impacts. Materials and Methods Model runs We use existing model runs of the Hadley Centre Global Environment Model version 3 (HadGEM3) in which a collapse of the AMOC was deliberately triggered by an influx of freshwater. The model and its performance have been described in detail elsewhere 62 but briefly, it is the Global Coupled 2.0 model (GC2) configuration of the HadGEM3 model 63 which consists of coupled models for atmosphere, ocean, sea-ice and land-surface. Details of the experimental setup and runs we analyze here have been described previously 1 , 64 , 65 . Two runs of the model are compared to isolate the effects of the collapse of the AMOC: 1) a steady state preindustrial control run where the AMOC is in its usual on state, and 2) an AMOC off run (the absence of the sinking branch of the AMOC is what we will refer to as the ‘AMOC off’ state). The AMOC is collapsed using the method described by Jackson et al (2015) 1 . This involves perturbing the salinity in the upper layers of the North Atlantic to inhibit deep convection and thus leading to a rapid shut down the AMOC. Although this method of collapsing the AMOC is unrealistic, it is useful for investigating the impacts of a shutdown. The salinity perturbations are applied to the upper 536 m of the Atlantic and Arctic Oceans north of 20°N each December for the first 10 years. Each salinity perturbation is equivalent to continuously adding freshwater at a rate of 1Sv for 10 years (total of 10 SvYr). To give an idea of the size of this annual perturbation, a freshwater flux from the Greenland ice sheet of 1Sv would melt it completely in 9 years. The AMOC off run is integrated for a total of 450 years from the start of the salinity perturbations. No external forcing is applied to the model apart from diurnal and annual cycles of the radiative fluxes and atmospheric CO 2 concentrations are fixed to preindustrial levels. As the perturbations are applied, the AMOC collapses from the steady ~ 15 Sv (maximum stream function at 26.5°N) in the control run and remains very weak throughout the 450-year model simulation period. As a result, Atlantic meridional ocean heat transport at 30°N is halved from ~ 1 to ~ 0.5 PW and the surface air temperature (SAT) decreases by ~ 4°C in the North Atlantic 1 . The AMOC off simulation is approximately stationary 60 years after the cessation of salinity perturbations. The maximum in the AMOC streamfunction at 26.5°N has a very slow increasing trend reaching ~ 5 Sv at the end of the 450 years. However, further north the AMOC shows no signs of recovery 65 . We first isolate the climatic impacts of an AMOC-collapse without accounting for the additional global warming most likely to trigger a collapse. The isolated impacts of an AMOC collapse are analyzed by taking the difference of 30-year means of the control run and the AMOC off run once the simulation is approximately stationary. We expand our analysis to include the impacts of an AMOC collapse against a more realistic future climate state, accounting for the additional effects of global warming corresponding to the scenario SSP1-2.6 in the model HadGEM3 66 . The model has the same atmospheric and ocean resolutions as used in the AMOC hosing experiments. The scenario SSP1-2.6 refers to Shared Socioeconomic Pathway SSP1 and Regional Concentration Pathway RCP2.6 - a low emissions pathway with high sustainability 67 . Under this scenario, the model reaches a mean global warming of 2.5°C above pre-industrial levels by the end of the century (2071–2100). This level of warming represents the ensemble mean for end of century warming based on 2030 NDC targets 68 . We overlay this warming pattern on the impacts of an AMOC collapse by taking a linear combination of the two model runs to establish the overall impact if the AMOC were to collapse after 2.5°C global warming. A key caveat is that this linear combination approach does not account for potential non-linear interactions and feedbacks that could occur when compounding such major climate system perturbations. For example, the Arctic cooling from an AMOC collapse is likely overestimated in our combined scenario, as the ice-albedo feedback would be dampened when Arctic sea ice loss has already occurred under the warming scenario. Additionally, linearly adding the reorganization of tropical precipitation patterns from AMOC collapse to the drying trend under warming may distort the actual shift in the tropics. While challenging to fully represent, capturing these non-linear effects is important for accurately quantifying magnitudes of change. Human niche calculation Following the approach from Xu et al (2020), we characterized the human climate niche using global gridded human population datasets and a range of social and environmental variables. We used both current population data and reconstructed population data from the History Database of the Global Environment (HYDE 3.1) 69 . We used the 2020 population density distribution as a baseline for constructing the human climate niche 43 . The population density distribution with respect to mean annual temperature (MAT) and mean annual precipitation (MAP) is assumed to sum to unity, providing a normalized measure. We modeled the realized human climate niche based on double-Gaussian fitting of the running mean of the current population distribution against MAT and MAP. We then projected the modeled niche to the alternative climate conditions (AMOC off and AMOC off plus warming) to illustrate the potential geographic shift of the human climate niche. Changes in climate “suitability” are then calculated as the proportions of summed niche gain or loss using 30-year means of the control run and the AMOC-off run, once the simulation is approximately stationary. The global “suitability” for human populations in AMOC-on and AMOC-off scenarios are then mapped. The change in the human climate niche is presented as the difference between the calculated climate niche for the AMOC-on control run, which is representative of a pre-industrial world, and the climate niche after future scenario simulation experiments. Declarations Author Contributions: J.F.A. and T.M.L. designed research; J.F.A., C.X., C.A.B., T.M.L., and P.R. performed research; J.F.A. and C.X. analyzed data; J.F.A. wrote the first draft; T.M.L., C.X., M.S., M.S.W., M.R., and A.G. commented on all versions of the manuscript; T.M.L., C.X., M.S. contributed by suggesting novel additional analyses and interpretations. Competing Interest Statement: The authors declare no competing interests. Data availability: All data and scripts used to generate the results presented in this paper are either accessible via cited sources or can be found on this repository: www.xyz.com. Acknowledgments: This work was supported by the Organisation for Economic Co-operation and Development (OECD). JFA, CAB, and TML were supported by a grant under the DARPA ACTM AIE program (DARPA-PA-21-04-02 award number HR0011-22-9-0031). JFA, AG, and TML were supported by an Open Society Initiative grant (award reference OR2021-82956). JFA, CAB, and TML are also supported by the Bezos Earth Fund. CX was supported by the National Natural Science Foundation of China (32061143014) and the Fundamental Research Funds for the Central Universities (9610065). MSW and PDLR were supported by the European Research Council (ERC) ECCLES project, grant agreement number 742472. CAB, PDLR and TML were supported by the Optimal High Resolution Earth System Models for Exploring Future Climate Changes (OptimESM) project, grant agreement number 101081193. CAB, PDLR and TML were supported by the NERC Valuing Nature programme (NE/P007880/1). LJ was supported by the Met Office Hadley Centre Climate Programme funded by DSIT. We would like to thank Dr. Marcia Rocha for her valuable input. References Jackson, L. C. et al. Global and European climate impacts of a slowdown of the AMOC in a high resolution GCM. Clim. Dyn. 45 , 3299–3316 (2015). Dietz, S., Rising, J., Stoerk, T. & Wagner, G. Economic impacts of tipping points in the climate system. Proc Natl Acad Sci USA 118 , (2021). Anthoff, D., Estrada, F. & Tol, R. S. J. Shutting down the thermohaline circulation. American Economic Review 106 , 602–606 (2016). Link, P. M. & Tol, RichardS. J. Possible economic impacts of a shutdown of the thermohaline circulation: an application of FUND. Port. Econ. J. 3 , (2004). 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The met office global coupled model 3.0 and 3.1 (GC3.0 and GC3.1) configurations. J. Adv. Model. Earth Syst. 10 , 357–380 (2018). Riahi, K. et al. The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An overview. Global Environmental Change 42 , 153–168 (2017). Climate Action Tracker. Warming Projections Global Update . (2023). Klein Goldewijk, K., Beusen, A., Van Drecht, G. & De Vos, M. The HYDE 3.1 spatially explicit database of human-induced global land-use change over the past 12,000 years. Glob. Ecol. Biogeogr. 20 , 73–86 (2011). Additional Declarations There is NO Competing Interest. Supplementary Files AMOCcollapsenicheSI.docx Supplementary Information Cite Share Download PDF Status: Under Review 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. 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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-4402479","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":316960215,"identity":"74cc4954-5406-43d2-a406-f95491974603","order_by":0,"name":"Jesse Abrams","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6ElEQVRIie2RsQrCMBCGrxTiUujaLPUVGoSKU18lpeALONihQ6RgluLs5is4dW4R0iUPoAREEZydxKlodXOIHR3yTcfdfXA/B2Aw/CEWA/Qu3K9uDwV3W1Uf5cVHCaq+is3s6yXNymjUFORyS4/g8grhtfYwNCZSqLiUIgkqOQNPUoS3+iwhZkjRcJ8Ir15SgD0gfNIqgztmrYpGmzN/1C2F4W/FCfFiqaytZwuoGYWgU7SH5c6cLFYqXstp4klBHSLjfKKLTzgvz+yuIpdLcksz6vvNrj4UOiX/ajg/HznUTg0Gg8HQ8QTmulAcX2KrbQAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-0411-8519","institution":"University of Exeter","correspondingAuthor":true,"prefix":"","firstName":"Jesse","middleName":"","lastName":"Abrams","suffix":""},{"id":316960216,"identity":"87f99776-0543-4e1f-9479-bb34afb3d354","order_by":1,"name":"Chi Xu","email":"","orcid":"https://orcid.org/0000-0002-1841-9032","institution":"Nanjing University","correspondingAuthor":false,"prefix":"","firstName":"Chi","middleName":"","lastName":"Xu","suffix":""},{"id":316960217,"identity":"352511be-69c1-48d0-af3a-b64b4a8d2732","order_by":2,"name":"Chris Boulton","email":"","orcid":"https://orcid.org/0000-0001-7836-9391","institution":"University of Exeter","correspondingAuthor":false,"prefix":"","firstName":"Chris","middleName":"","lastName":"Boulton","suffix":""},{"id":316960218,"identity":"a40b1d13-6d49-46b6-8f89-4ec6d6a7baaa","order_by":3,"name":"Marten Scheffer","email":"","orcid":"https://orcid.org/0000-0002-2100-0312","institution":"Wageningen University \u0026 Research","correspondingAuthor":false,"prefix":"","firstName":"Marten","middleName":"","lastName":"Scheffer","suffix":""},{"id":316960219,"identity":"2383fec1-0c3e-4183-a14d-c65f90f5e769","order_by":4,"name":"Paul Ritchie","email":"","orcid":"https://orcid.org/0000-0002-7649-2991","institution":"University of Exeter","correspondingAuthor":false,"prefix":"","firstName":"Paul","middleName":"","lastName":"Ritchie","suffix":""},{"id":316960220,"identity":"da580812-9327-4fcf-af54-643286d0469e","order_by":5,"name":"Mark Williamson","email":"","orcid":"https://orcid.org/0000-0002-4548-8922","institution":"University of Exeter","correspondingAuthor":false,"prefix":"","firstName":"Mark","middleName":"","lastName":"Williamson","suffix":""},{"id":316960221,"identity":"96ef9284-4b93-4e09-bb57-95c6efea3085","order_by":6,"name":"Ashish Ghadiali","email":"","orcid":"","institution":"University of Exeter","correspondingAuthor":false,"prefix":"","firstName":"Ashish","middleName":"","lastName":"Ghadiali","suffix":""},{"id":316960222,"identity":"c93e9de9-929b-429b-b417-154199f54202","order_by":7,"name":"Laura Jackson","email":"","orcid":"https://orcid.org/0000-0003-2326-305X","institution":"UK Met Office","correspondingAuthor":false,"prefix":"","firstName":"Laura","middleName":"","lastName":"Jackson","suffix":""},{"id":316960223,"identity":"9220b54c-148c-429d-b166-d33b49a646bb","order_by":8,"name":"Jennifer Mecking","email":"","orcid":"https://orcid.org/0000-0002-1834-1845","institution":"National Oceanography Centre","correspondingAuthor":false,"prefix":"","firstName":"Jennifer","middleName":"","lastName":"Mecking","suffix":""},{"id":316960224,"identity":"2c9015b1-3ebc-42d2-9051-3d9c21013620","order_by":9,"name":"Timothy Lenton","email":"","orcid":"https://orcid.org/0000-0002-6725-7498","institution":"University of Exeter","correspondingAuthor":false,"prefix":"","firstName":"Timothy","middleName":"","lastName":"Lenton","suffix":""}],"badges":[],"createdAt":"2024-05-10 20:05:38","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4402479/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4402479/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":61765118,"identity":"ae37721e-de92-4ad1-9ae1-7b82592dfab0","added_by":"auto","created_at":"2024-08-05 10:19:32","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":191694,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eChanges in the modeled human MAT-MAP niche due to global warming and a climate tipping point.\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e The change in human suitability as a result of (A) 2.5ºC global warming, (B) the hypothetical AMOC collapse in isolation, (C) the cumulative effect of AMOC collapse triggered by 2.5ºC global warming. The climate niches are calculated using 30-year means of the control run and the AMOC-off run, once the simulation is approximately stationary, performed by the HadGEM3 model. The isolated impacts of the AMOC collapse is a theoretical simulation as additional warming or other forcing would be necessary to trigger the collapse of the AMOC.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4402479/v1/dd1c99e279b7cbe3bafb1fd8.png"},{"id":61764438,"identity":"1b7c1eb1-5f57-4581-a7d2-d8aa4c7808c7","added_by":"auto","created_at":"2024-08-05 10:11:32","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":94275,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eSign of changes in suitability of the human climate niche due to AMOC collapse following ~2.5ºC global warming.\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e In some areas the effects of warming on suitability in terms of the human climate niche will be amplified by the effects of AMOC collapse (whether the changes in human suitability are either both negative (red) or both positive (blue)). In other areas they will have opposing effects on climate niche suitability (pink and purple). Although in some cases the effects may offset each other, this masks the adaptation challenges presented by serial shifts in climatic conditions that represent different adaptation challenges. Much of the world would be confronted by this challenge. Here, we do not indicate the amplitude of the effects, but only the direction (positive or negative) of the impact on human suitability.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4402479/v1/7d0d2c4c9873d918a2d2b697.png"},{"id":61764440,"identity":"c50926a4-6d26-4951-8936-1eef654a0c69","added_by":"auto","created_at":"2024-08-05 10:11:32","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":248690,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eSankey diagram showing the population that experiences a loss or gain in niche suitability compared to the control. \u003c/strong\u003e\u003c/em\u003e\u003cem\u003e(A) Shows the shifts in suitability due to warming and the subsequent shift due to AMOC collapse while (B) illustrates the combined suitability shift. The chart illustrates the exposure to divergent shifts in suitability due to the impacts of warming and the combined impacts of warming and AMOC collapse. While it may appear that conditions improve in the combined scenario, many people experience divergent serial shifts in conditions. This will lead to severe adaptation challenges and render many adaptation measures maladaptive.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4402479/v1/ec5d48bfaadc09b3e0512772.png"},{"id":61764443,"identity":"94db5bb4-3d55-4ec1-82df-0efe27da07c4","added_by":"auto","created_at":"2024-08-05 10:11:33","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":115819,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eThe largest country-level positive and negative changes in human suitability. \u003c/strong\u003e\u003c/em\u003e\u003cem\u003eChanges in suitability of the human climate niche are presented for the 2.5C global warming, AMOC collapse, and combined scenarios. Results are filtered and presented in rank order for the combined global warming and AMOC collapse scenarios. Panels A, B and Panels C, D show the 20 countries with the highest average increase and decrease in suitability in the Northern Hemisphere extra tropics and Southern Hemisphere extra tropics, respectively. Panels E and F show the countries and territories located in the tropics that have an average increase and decrease in suitability, respectively.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4402479/v1/b0c9458a16898c82d76996f7.png"},{"id":61765994,"identity":"82f7151d-0ad9-4170-85dd-426237a5a48a","added_by":"auto","created_at":"2024-08-05 10:27:33","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1456169,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4402479/v1/20792ad9-1546-4f4a-a260-5e65c4b68450.pdf"},{"id":61764442,"identity":"dbee14ff-5a7d-4fe3-ade5-0443aa2828b0","added_by":"auto","created_at":"2024-08-05 10:11:32","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":2409449,"visible":true,"origin":"","legend":"Supplementary Information","description":"","filename":"AMOCcollapsenicheSI.docx","url":"https://assets-eu.researchsquare.com/files/rs-4402479/v1/262d61a6821c8a05def468c5.docx"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Divergent impacts of ocean tipping and global warming on habitability","fulltext":[{"header":"Main","content":"\u003cp\u003eThe Atlantic Meridional Overturning Circulation (AMOC) - part of the global ocean thermohaline circulation - plays a crucial role in the circulation patterns that influence global temperature and precipitation. While there is uncertainty \u003csup\u003e9,10\u003c/sup\u003e, some observational evidence suggests that the AMOC has weakened by around 15 percent in recent decades, is at its weakest point in the last 1,600 years and that this weakening may be accelerating \u003csup\u003e11–14\u003c/sup\u003e. Ongoing freshwater influx in the North Atlantic may inhibit deep water formation resulting in a continuing weakening - or even collapse - of the AMOC \u003csup\u003e15–17\u003c/sup\u003e. This would represent a fundamental reorganization of ocean circulation, causing a redistribution of heat around the planet and a corresponding coupled response from the atmosphere \u003csup\u003e18\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThe IPCC consensus is that while the AMOC will “very likely” (90-100%) weaken later this century, it is “very unlikely” (\u0026lt;10%) to collapse within this century \u003csup\u003e19\u003c/sup\u003e. However, others consider the risk of AMOC collapse to become significant between 2-3°C global warming \u003csup\u003e16,20,21\u003c/sup\u003e. Recent research estimated that AMOC is on course to collapse \u003csup\u003e22\u003c/sup\u003e and this could occur between 2025 and 2095, with a central estimate of 2050, if global carbon emissions are not reduced \u003csup\u003e20\u003c/sup\u003e. Here we assess the impacts of a collapse of the AMOC at 2-3°C global warming above pre-industrial temperature. A world in which the global mean temperature is 2.5°C warmer than pre-industrial times is representative of where we will end up later this century under current legally-binding policies \u003csup\u003e23\u003c/sup\u003e. Crossing an AMOC tipping point would have major global ramifications. These include a drastic cooling of western Europe, a reduction of rainfall in the Atlantic region and a shift in the intertropical convergence zone shifting rainfall southwards. The change in ocean circulation patterns would affect marine ecosystems and give faster sea level rise along the Northeast seaboard of North America and parts of Europe. Stronger hurricanes in the Southeastern United States and the Caribbean, and reduced rainfall across the Sahel have also been predicted \u003csup\u003e1,24–27\u003c/sup\u003e. It could also trigger tipping points in the Amazon and have significant impacts on tropical monsoon systems \u003csup\u003e28–32\u003c/sup\u003e. Recent work indicates that, without the AMOC, the tropical Pacific Ocean cools, and trade winds intensify and shift south, putting the Earth in a climate state that resembles a permanent La Niña, which could trigger catastrophic monsoons and flooding in the South Pacific \u003csup\u003e33\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eAn AMOC collapse may thus represent an existential threat to humanity \u003csup\u003e34\u003c/sup\u003e. Some economic analyses have hypothesized that AMOC collapse would cause a 25-30% loss to GDP comparable with the Great Depression but irreversible \u003csup\u003e35\u003c/sup\u003e. However, other economic analyses have suggested that despite the possibility of wide-reaching economic and human impacts, the impact on GDP may be small or even positive \u003csup\u003e2–4\u003c/sup\u003e. A key weakness across these studies, which rely on simple Integrated Assessment Models (IAMs), is the overlooking of precipitation changes and within-country climate variations in favor of a narrow focus on temperature impacts on GDP. This fails to account for substantially different climate change effects in subregions. Further, this approach does not account for the impacts of potentially divergent directions of climate change due to diverse processes. There are many recognised problems with simple integrated assessment model representation of the impacts of climate change and especially tipping points \u003csup\u003e5,36–40\u003c/sup\u003e. Most fundamentally, they tend to conflate weather variability with long-term climate changes \u003csup\u003e5,41\u003c/sup\u003e and apply spatial analogues across different geographic and temporal scales. This false equivalence ignores the fact that climate change involves systematic shifts in baseline weather patterns over multi-decadal time spans, with profound economic implications relating to infrastructure, supply chains, and more. Much of the existing work often assumes that human economies are highly adaptable to climate change, implying minimal economic impacts, but this method does not fully account for the possibility of large-scale, nonlinear changes like tipping points, and the potential for successive climate regime shifts in different directions may challenge the presumption of high adaptability, testing the limits of social and economic resilience even with humanity's capacity to adjust.\u003c/p\u003e\n\u003cp\u003eAs an alternative to the use of IAMs, the human climate niche \u003csup\u003e7\u003c/sup\u003e takes an ecological approach to quantify how human population density depends on mean annual temperature (MAT) and mean annual precipitation (MAP). This concept, analogous to the ecological niche occupied by a species \u003csup\u003e42\u003c/sup\u003e, has been used to characterize the climatic conditions suitable for human societies \u003csup\u003e7,8\u003c/sup\u003e. The niche is found to be conserved over centuries \u003csup\u003e8\u003c/sup\u003e, with similar relationships between climate and human population density, crop yields, livestock distributions, and economic productivity observed across different historical periods. As such, the climate niche provides a simple, integrated way of starting to consider the impacts of temperature and precipitation on human habitability. However it does not capture the impact of sea level rise and lacks explicit representation of the effects of seasonality or extremes.\u003c/p\u003e\n\u003cp\u003eWe examine the impacts of 2.5°C global warming and AMOC collapse independently and then in combination. We show how these successive large-scale shifts in global climate conditions in conflicting directions would challenge humanity's capacity to adapt in many regions. \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eProjected Change\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOur study examines HadGEM3-GC2 model scenarios portraying the impacts of 2.5°C global warming under SSP1-2.6, isolated AMOC collapse, and AMOC collapse following 2.5°C global warming. The latter scenario is produced by a linear combination of the previous ones and as such misses some key non-linear effects. For instance, the simulated cooling in high northern latitudes will be overstated due to more strongly amplified sea-ice growth in the control climate than in a warmer world where much ice has been lost. The scenario of AMOC collapse alone remains theoretical, requiring additional warming or freshwater forcing for a full collapse. Our previous work considered the 2015 population distribution under the 1960–1990 mean climate as a baseline \u003csup\u003e8\u003c/sup\u003e and the 1980 population distribution under the 1960–1990 mean climate as the reference state \u003csup\u003e7\u003c/sup\u003e. Here our analysis of changes in the human climate niche is based on deviations from a control scenario representative of the 1990-2020 climatological mean and uses the 2020 population. The 1990-2020 mean better represents recent climatological conditions that human systems are adapted to and is more relevant for assessing deviations caused by an AMOC collapse that may occur in the upcoming decades.\u003c/p\u003e\n\u003cp\u003eUnder SSP1-2.6, our model projects a 2.5°C warming by the end of the century. As shown by Xu et al. (2020)\u003csup\u003e8\u003c/sup\u003e and Lenton et al. (2023)\u003csup\u003e7\u003c/sup\u003e this warming will disproportionately impact the tropics. The projected geographical shift of favorable MAT-MAP conditions over the rest of the century is substantial, with optimal conditions for humans projected to move poleward and with the worst effects in the tropics and some extra-tropical regions (Figure 1A). \u003c/p\u003e\n\u003cp\u003eWhile AMOC collapse in isolation remains a hypothetical scenario, it provides valuable insights into the isolated impacts of this tipping point. Our simulations show that AMOC collapse would cause striking geographical shifts in the human climate niche (Figure 1B), disproportionately affecting the Northern Hemisphere, particularly Europe. In these simulations, Europe and higher northern latitudes experience significant cooling of up to 8°C, while the Southern Hemisphere experiences little to no warming (Figure S1A). Furthermore, most of the Northern Hemisphere experiences drying, except for North America, which becomes slightly wetter on average (Figure S1B). Notably, there are disruptions to the Indian summer monsoon and significant drying in the Amazon basin, highlighting potential cascading effects. On a global scale, regions in the tropics and south of the equator become more habitable on average, while habitability decreases in the Global North, particularly in higher latitudes (Figure 1B). Sub-Saharan Africa, as well as Central and South America, see the largest gain in habitability. \u003c/p\u003e\n\u003cp\u003eIn the combined scenario of 2.5°C global warming followed by AMOC collapse (Figure 1C), the average change in population-weighted human experienced temperature is +0.7°C. This scenario exhibits contrasting temperature responses between higher northern latitudes and the tropics and Southern Hemisphere (Figure S1A). Precipitation patterns also differ, with reduced precipitation in the Northern Hemisphere and increased precipitation in the Southern Hemisphere. Europe emerges as the most negatively impacted region, experiencing both cooling and reduced precipitation. North America becomes mostly more suitable due to a negligible change in temperature from the combined effects of 2.5°C and AMOC collapse, accompanied by a general increase in precipitation. Large swaths of South America, particularly Brazil, become less suitable due to amplification of two factors under the combined 2.5°C warming and AMOC collapse scenario - a reduction in precipitation and increase in temperature making the region hotter and dryer. Relative to the warming only scenario, suitability in most of sub-saharan Africa increases due to increases in rainfall, while equatorial Africa and Northern Africa - where the impact is dominated by the temperature increase in the warming scenario - see a marked decrease in suitability. \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSerial Shifts\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOur analysis shows that while a 2.5°C global warming leads to widespread temperature increases across both hemispheres, the shutdown of the AMOC triggers divergent temperature responses (Figure S1A). Initially, extratropical latitudes in the Northern Hemisphere warm, followed by widespread cooling due to AMOC shutdown. In contrast, the tropics and the Southern Hemisphere experience widespread warming. These serial shifts in the climate niche highlight the complexity of the impacts, especially in regions like the Northern Hemisphere extratropics, where opposing temperature changes occur. \u003c/p\u003e\n\u003cp\u003eWhile a few regions may experience amplified effects of AMOC collapse on the human climate niche compared to warming alone (Figure 2), overall, AMOC collapse predominantly shifts the climate niche in the opposite direction of warming. This means that where warming has a positive impact on the MAT-MAP niche, AMOC collapse will have a negative impact, and vice versa. While some regions like northern Europe exhibit amplified cooling under the combined scenario compared to AMOC collapse alone, the predominant pattern is one of divergence rather than amplification of effects. For instance, parts of Canada experience warming of 2-4°C under 2.5°C, but this is almost entirely negated by the 2-6°C cooling from an AMOC collapse. This realignment of temperature regimes from one extreme to the other within a relatively short period poses significant challenges for adaptation.\u003c/p\u003e\n\u003cp\u003eThe serial reversals are even starker when examining the spatial context of precipitation changes. The US Southwest is projected to experience over 20% drying under 2.5°C warming, potentially straining water resources. However, an AMOC collapse could increase rainfall by 10-20% in this region, rendering any incremental adaptations for drought conditions maladaptive. Globally, changes in suitability are compounding for 27% of the global population, while changes in suitability oppose each other for 73% of population.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eHuman Exposure\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo illustrate climatic shifts and human exposure changes, we analyze the MAP-MAT niche relative to the 2020 population distribution\u003csup\u003e43\u003c/sup\u003e (Figure S3). Under a scenario of 2.5°C global warming combined with AMOC collapse (Figure S3A), reduced precipitation decreases suitability in densely populated regions like western Europe, eastern North America, the Amazon, and western Africa (Figure 3). Conversely, suitability increases in less populated regions like southern Africa, parts of South America, and south Asia. Similar trends occur with MAT changes (Figure S3B), showing suitability increases in sparsely inhabited higher latitudes but decreases in densely populated temperate and tropical zones. Overlaying niche shifts with population maps reveals significant human exposures to declining suitability conditions in major population clusters, such as urban zones in Southeast Asia and India, due to the compounding impacts of warming and AMOC collapse.\u003c/p\u003e\n\u003cp\u003eProjections of climate niche shifts under a global warming followed by AMOC collapse scenario unveil winners and losers (Figure 4). Under 2.5°C global warming alone, the tropics and Southern Hemisphere face substantial declines in suitability compared to higher northern latitudes. In a combined scenario, countries across all regions experience both increases (Figure 4A) and decreases (Figure 4B) in suitability, with Europe emerging as a significant loser. Some countries, like Zimbabwe and Botswana, experience compounding gains initially due to favorable shifts following prior warming, reinforced by AMOC collapse. However, this may be short-lived if subsequent warming exceeds habitability thresholds, particularly affecting regions in the Global South.\u003c/p\u003e"},{"header":"Discussion and conclusions","content":"\u003cp\u003ePrevious research indicates that the tropics may face greater climate impact burdens compared to the extratropical regions in the Northern Hemisphere as temperatures surpass optimal human conditions in more areas \u003csup\u003e\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e. Here we show an AMOC collapse could alter this picture, causing large shifts in climate suitability elsewhere, especially in Europe, and altering the direction of change in climate suitability in many regions. This poses a major adaptation challenge, as regions adapting to one trend in conditions may abruptly face a reversal, stressing natural and human adaptive capacities and potentially rendering some adaptations maladaptive \u003csup\u003e\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e,\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u003c/sup\u003e. For example, poleward migration of agricultural production in Europe (as is already observed) \u003csup\u003e\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u003c/sup\u003e would become extremely maladaptive after a tipping point of AMOC collapse. Similarly in the Southern States of the US, declining climate suitability would be abruptly reversed. The exact numerical values will depend on the specific model and scenario assumptions, but the general patterns of temperature and precipitation impacts are expected to be robust because similar patterns of change are seen for forced AMOC collapse simulations across different general circulation models (GCMs) \u003csup\u003e\u003cspan additionalcitationids=\"CR49\" citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eSome nations like the United Kingdom, Netherlands, and Spain emerge as acute \"losers,\" with climate conditions becoming substantially less suitable due to the cooling and drying effects of AMOC collapse compounding the initial warming impacts. Conversely, parts of southern Africa and South America experience increases in suitability as AMOC changes offset some of the detrimental warming effects in those regions. However, these conditions may prove short-lived and could lead to maladaptation if temperatures subsequently exceed human habitability thresholds due to continued warming \u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe tropics merit particular attention given their vulnerability to climate change highlighted in the introduction. While some tropical regions like parts of South America face warming further compounded by drying from AMOC impacts, the core tropical regions experience a more mixed signal. Offsetting effects which may appear beneficial in the near-term, like rainfall increases counteracting warming, could ultimately prove transient if temperatures continue rising past human habitability thresholds. These complexities underscore the need for granular, systems-based risk assessments accounting for interactions across sectors and scales. There are some important limitations to our approach of using annual mean temperature and precipitation changes. Large seasonal changes in precipitation are seen locally in the tropics with an AMOC collapse, and this pronounced seasonality could have important impacts on agricultural crops and other sectors that are missed by looking at annual means. Extremes are also not captured by this approach, which could lead to underestimating some of the impacts.\u003c/p\u003e \u003cp\u003eOverlay maps of projected climate niche shifts with current population distributions reveal substantial human exposure clusters facing declining habitability conditions. This includes urban centers across Southeast Asia, India, and parts of coastal West Africa, primarily driven by the compounding temperature increases under the combined warming and AMOC collapse scenario. However, the spatial redistribution also suggests potential migration corridors tracking niche shifts, both poleward in the northern hemisphere but also into regions made wetter by AMOC precipitation pattern changes. Quantifying these exposure hotspots and emergent population redistribution risks is critical for prioritizing adaptation efforts and infrastructure resilience investments.\u003c/p\u003e \u003cp\u003eIt is important to note that our approach of using annual mean temperature and precipitation changes has some key limitations in capturing the full impacts. Specifically, it misses large seasonal variations as well as changes in extremes that could have very significant effects. For example, large seasonal changes in precipitation are projected in the tropics with an AMOC collapse, which could have major impacts on agricultural crops and other sectors. Additionally, an increase in extreme winter storms has been linked to AMOC collapse in regions like the UK, which is not reflected in the annual mean changes. These examples highlight that while our approach provides a reasonable first-order approximation, future work should include more comprehensive assessments that resolve seasonal cycles and extreme events.\u003c/p\u003e \u003cp\u003eWhile the responses in models forced by different forcings are generally additive, the approach of linearly combining the isolated warming and AMOC collapse scenarios does not account for non-linear feedbacks and interactions that would occur when compounding such major climate system perturbations \u003csup\u003e\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e. Therefore, caution is warranted regarding the exact magnitudes projected. Notably, the Arctic cooling is overestimated when AMOC collapse happens from a warmed baseline since the ice-albedo feedback would be dampened when ice loss has already occurred under warming \u003csup\u003e\u003cspan additionalcitationids=\"CR54\" citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e\u003c/sup\u003e. Since the warming scenario used already included some AMOC weakening, this linear recombination deviates from the assumption of separable effects. This may lead to an overestimation of the magnitudes of changes, such as European cooling, which would be tempered by residual warming and the lack of accounting for non-linear feedbacks and interactions. Additionally, linearly adding the AMOC's reorganization of tropical precipitation patterns to the global warming drying trend may obscure or distort the actual precipitation shift in the tropics.\u003c/p\u003e \u003cp\u003eThe adaptation literature highlights the challenges societies face in keeping pace with gradual climate changes \u003csup\u003e\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e\u003c/sup\u003e. If climate change itself adds to adaptation constraints and limits, then abrupt changes and reversals will prove to be even more disruptive, potentially overwhelming existing coping mechanisms, making long-term planning extremely difficult, and pushing us to the social limits for adaptation to climate change \u003csup\u003e\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e\u003c/sup\u003e. Any successful adaptations to the initial climate trend may become maladaptive. While a reasonable first order approximation of the impact of global warming \u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e, the use of annual mean temperature and precipitation to define the \"human climate niche\" simplifies complex impacts in regions with large seasonal cycles or extreme events, which would further stress adaptive capacity \u003csup\u003e\u003cspan additionalcitationids=\"CR59\" citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eOur results illustrate that simplistic assumptions about the geographic distribution of climate impacts and adaptation needs in many economic models may miss critically important aspects. An AMOC collapse could produce successive, opposing climate shifts in some regions, challenging assumptions of gradual adaptation built into models evaluating damages solely through temperature impacts on national GDP growth. Instead of the current approach, systemic risk assessment that accounts for potential non-linear, spatially heterogeneous impacts is necessary to evaluate serial climate shifts and develop robust adaptation strategies \u003csup\u003e\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e\u003c/sup\u003e. To better assess tipping risks, economic models should move beyond linking nationally-averaged temperature changes to GDP impacts. Representing potential for abrupt, heterogeneous changes across regions is important, rather than assuming globally well-mixed conditions. While challenging, capturing these complex dynamics is crucial for developing adequate climate risk management strategies.\u003c/p\u003e \u003cp\u003eDespite simplifications, this analysis provides an integrated perspective on potential disruptive climate interactions, motivating further research to better constrain magnitudes and represent relevant feedbacks. We highlight the potential for profoundly uneven human impacts from an AMOC collapse triggered by global warming.The possibility of undergoing successive large-scale climate regime shifts in alternating directions presents an unprecedented challenge that requires rethinking how we model and evaluate climate impacts.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eModel runs\u003c/h2\u003e \u003cp\u003eWe use existing model runs of the Hadley Centre Global Environment Model version 3 (HadGEM3) in which a collapse of the AMOC was deliberately triggered by an influx of freshwater. The model and its performance have been described in detail elsewhere \u003csup\u003e\u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e\u003c/sup\u003e but briefly, it is the Global Coupled 2.0 model (GC2) configuration of the HadGEM3 model \u003csup\u003e\u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e63\u003c/span\u003e\u003c/sup\u003e which consists of coupled models for atmosphere, ocean, sea-ice and land-surface.\u003c/p\u003e \u003cp\u003eDetails of the experimental setup and runs we analyze here have been described previously \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e64\u003c/span\u003e,\u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e65\u003c/span\u003e\u003c/sup\u003e. Two runs of the model are compared to isolate the effects of the collapse of the AMOC: 1) a steady state preindustrial control run where the AMOC is in its usual on state, and 2) an AMOC off run (the absence of the sinking branch of the AMOC is what we will refer to as the \u0026lsquo;AMOC off\u0026rsquo; state). The AMOC is collapsed using the method described by Jackson et al (2015) \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. This involves perturbing the salinity in the upper layers of the North Atlantic to inhibit deep convection and thus leading to a rapid shut down the AMOC. Although this method of collapsing the AMOC is unrealistic, it is useful for investigating the impacts of a shutdown.\u003c/p\u003e \u003cp\u003eThe salinity perturbations are applied to the upper 536 m of the Atlantic and Arctic Oceans north of 20\u0026deg;N each December for the first 10 years. Each salinity perturbation is equivalent to continuously adding freshwater at a rate of 1Sv for 10 years (total of 10 SvYr). To give an idea of the size of this annual perturbation, a freshwater flux from the Greenland ice sheet of 1Sv would melt it completely in 9 years. The AMOC off run is integrated for a total of 450 years from the start of the salinity perturbations. No external forcing is applied to the model apart from diurnal and annual cycles of the radiative fluxes and atmospheric CO\u003csub\u003e2\u003c/sub\u003e concentrations are fixed to preindustrial levels. As the perturbations are applied, the AMOC collapses from the steady\u0026thinsp;~\u0026thinsp;15 Sv (maximum stream function at 26.5\u0026deg;N) in the control run and remains very weak throughout the 450-year model simulation period. As a result, Atlantic meridional ocean heat transport at 30\u0026deg;N is halved from ~\u0026thinsp;1 to ~\u0026thinsp;0.5 PW and the surface air temperature (SAT) decreases by ~\u0026thinsp;4\u0026deg;C in the North Atlantic \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. The AMOC off simulation is approximately stationary 60 years after the cessation of salinity perturbations. The maximum in the AMOC streamfunction at 26.5\u0026deg;N has a very slow increasing trend reaching\u0026thinsp;~\u0026thinsp;5 Sv at the end of the 450 years. However, further north the AMOC shows no signs of recovery \u003csup\u003e\u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e65\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eWe first isolate the climatic impacts of an AMOC-collapse without accounting for the additional global warming most likely to trigger a collapse. The isolated impacts of an AMOC collapse are analyzed by taking the difference of 30-year means of the control run and the AMOC off run once the simulation is approximately stationary. We expand our analysis to include the impacts of an AMOC collapse against a more realistic future climate state, accounting for the additional effects of global warming corresponding to the scenario SSP1-2.6 in the model HadGEM3 \u003csup\u003e66\u003c/sup\u003e. The model has the same atmospheric and ocean resolutions as used in the AMOC hosing experiments. The scenario SSP1-2.6 refers to Shared Socioeconomic Pathway SSP1 and Regional Concentration Pathway RCP2.6 - a low emissions pathway with high sustainability \u003csup\u003e\u003cspan citationid=\"CR67\" class=\"CitationRef\"\u003e67\u003c/span\u003e\u003c/sup\u003e. Under this scenario, the model reaches a mean global warming of 2.5\u0026deg;C above pre-industrial levels by the end of the century (2071\u0026ndash;2100). This level of warming represents the ensemble mean for end of century warming based on 2030 NDC targets \u003csup\u003e\u003cspan citationid=\"CR68\" class=\"CitationRef\"\u003e68\u003c/span\u003e\u003c/sup\u003e. We overlay this warming pattern on the impacts of an AMOC collapse by taking a linear combination of the two model runs to establish the overall impact if the AMOC were to collapse after 2.5\u0026deg;C global warming.\u003c/p\u003e \u003cp\u003eA key caveat is that this linear combination approach does not account for potential non-linear interactions and feedbacks that could occur when compounding such major climate system perturbations. For example, the Arctic cooling from an AMOC collapse is likely overestimated in our combined scenario, as the ice-albedo feedback would be dampened when Arctic sea ice loss has already occurred under the warming scenario. Additionally, linearly adding the reorganization of tropical precipitation patterns from AMOC collapse to the drying trend under warming may distort the actual shift in the tropics. While challenging to fully represent, capturing these non-linear effects is important for accurately quantifying magnitudes of change.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eHuman niche calculation\u003c/h2\u003e \u003cp\u003eFollowing the approach from Xu et al (2020), we characterized the human climate niche using global gridded human population datasets and a range of social and environmental variables. We used both current population data and reconstructed population data from the History Database of the Global Environment (HYDE 3.1) \u003csup\u003e\u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e69\u003c/span\u003e\u003c/sup\u003e. We used the 2020 population density distribution as a baseline for constructing the human climate niche \u003csup\u003e\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. The population density distribution with respect to mean annual temperature (MAT) and mean annual precipitation (MAP) is assumed to sum to unity, providing a normalized measure. We modeled the realized human climate niche based on double-Gaussian fitting of the running mean of the current population distribution against MAT and MAP. We then projected the modeled niche to the alternative climate conditions (AMOC off and AMOC off plus warming) to illustrate the potential geographic shift of the human climate niche. Changes in climate \u0026ldquo;suitability\u0026rdquo; are then calculated as the proportions of summed niche gain or loss using 30-year means of the control run and the AMOC-off run, once the simulation is approximately stationary. The global \u0026ldquo;suitability\u0026rdquo; for human populations in AMOC-on and AMOC-off scenarios are then mapped. The change in the human climate niche is presented as the difference between the calculated climate niche for the AMOC-on control run, which is representative of a pre-industrial world, and the climate niche after future scenario simulation experiments.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u0026nbsp;\u003c/strong\u003eJ.F.A. and T.M.L. designed research; J.F.A., C.X., C.A.B., T.M.L., and P.R. performed research; J.F.A. and C.X. analyzed data; J.F.A. wrote the first draft; T.M.L., C.X., M.S., M.S.W., M.R., and A.G. commented on all versions of the manuscript; T.M.L., C.X., M.S. contributed by suggesting novel additional analyses and interpretations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interest Statement:\u0026nbsp;\u003c/strong\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability:\u0026nbsp;\u003c/strong\u003eAll data and scripts used to generate the results presented in this paper are either accessible via cited sources or can be found on this repository: www.xyz.com.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments:\u0026nbsp;\u003c/strong\u003eThis work was supported by the Organisation for Economic Co-operation and Development (OECD). JFA, CAB, and TML were supported by a grant under the DARPA ACTM AIE program (DARPA-PA-21-04-02 award number HR0011-22-9-0031). JFA, AG, and TML were supported by an Open Society Initiative grant (award reference OR2021-82956). JFA, CAB, and TML are also supported by the Bezos Earth Fund. CX was supported by the National Natural Science Foundation of China (32061143014) and the Fundamental Research Funds for the Central Universities (9610065). MSW and PDLR were supported by the European Research Council (ERC) ECCLES project, grant agreement number 742472. CAB, PDLR and TML were supported by the Optimal High Resolution Earth System Models for Exploring Future Climate Changes (OptimESM) project, grant agreement number 101081193. CAB, PDLR and TML were supported by the NERC Valuing Nature programme (NE/P007880/1). LJ was supported by the Met Office Hadley Centre Climate Programme funded by DSIT. We would like to thank Dr. Marcia Rocha for her valuable input.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eJackson, L. C. \u003cem\u003eet al.\u003c/em\u003e Global and European climate impacts of a slowdown of the AMOC in a high resolution GCM. \u003cem\u003eClim. Dyn.\u003c/em\u003e\u003cstrong\u003e45\u003c/strong\u003e, 3299\u0026ndash;3316 (2015).\u003c/li\u003e\n\u003cli\u003eDietz, S., Rising, J., Stoerk, T. \u0026amp; Wagner, G. Economic impacts of tipping points in the climate system. \u003cem\u003eProc Natl Acad Sci USA\u003c/em\u003e\u003cstrong\u003e118\u003c/strong\u003e, (2021).\u003c/li\u003e\n\u003cli\u003eAnthoff, D., Estrada, F. \u0026amp; Tol, R. S. J. Shutting down the thermohaline circulation. \u003cem\u003eAmerican Economic Review\u003c/em\u003e\u003cstrong\u003e106\u003c/strong\u003e, 602\u0026ndash;606 (2016).\u003c/li\u003e\n\u003cli\u003eLink, P. M. \u0026amp; Tol, RichardS. J. 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The HYDE 3.1 spatially explicit database of human-induced global land-use change over the past 12,000 years. \u003cem\u003eGlob. Ecol. Biogeogr.\u003c/em\u003e\u003cstrong\u003e20\u003c/strong\u003e, 73\u0026ndash;86 (2011).\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":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"tipping point, climate niche, displacement, adaptation","lastPublishedDoi":"10.21203/rs.3.rs-4402479/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4402479/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eThe potential collapse of the Atlantic Meridional Overturning Circulation (AMOC) poses substantial climate risks \u003c/strong\u003e\u003ca href=\"https://sciwheel.com/work/citation?ids=12386223\u0026amp;pre=\u0026amp;suf=\u0026amp;sa=0\"\u003e\u003csup\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/sup\u003e\u003c/a\u003e\u003cstrong\u003e, yet some current economic models estimate it would have a net economic benefit through counteracting the impacts of global warming that led to its collapse in the first place \u003c/strong\u003e\u003ca href=\"https://sciwheel.com/work/citation?ids=11930166,14845836,11408002\u0026amp;pre=\u0026amp;pre=\u0026amp;pre=\u0026amp;suf=\u0026amp;suf=\u0026amp;suf=\u0026amp;sa=0,0,0\"\u003e\u003csup\u003e\u003cstrong\u003e2–4\u003c/strong\u003e\u003c/sup\u003e\u003c/a\u003e\u003cstrong\u003e. This is based on eventual net effects on country-level mean annual temperature \u003c/strong\u003e\u003ca href=\"https://sciwheel.com/work/citation?ids=10478020,15909047\u0026amp;pre=\u0026amp;pre=\u0026amp;suf=\u0026amp;suf=\u0026amp;sa=0,0\"\u003e\u003csup\u003e\u003cstrong\u003e5,6\u003c/strong\u003e\u003c/sup\u003e\u003c/a\u003e\u003cstrong\u003e, with no consideration of effects on precipitation, spatial detail, or shifting directions of climate change. Here, we explore the impacts of consecutive climate shifts on the human climate niche \u003c/strong\u003e\u003ca href=\"https://sciwheel.com/work/citation?ids=14880883,8863621\u0026amp;pre=\u0026amp;pre=\u0026amp;suf=\u0026amp;suf=\u0026amp;sa=0,0\"\u003e\u003csup\u003e\u003cstrong\u003e7,8\u003c/strong\u003e\u003c/sup\u003e\u003c/a\u003e\u003cstrong\u003e – first 2.5°C global warming, disproportionately affecting the Global South, and then a collapse of the AMOC, impacting North Atlantic adjacent landmasses the most. We show that these sequential changes have very different spatial patterns of precipitation and temperature effects, some of which offset each other, while others are compounding. This represents a first step towards a more nuanced, spatially and temporally explicit approach to the quantification of the impacts of tipping a critical component of the climate system.\u003c/strong\u003e\u003c/p\u003e","manuscriptTitle":"Divergent impacts of ocean tipping and global warming on habitability","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-05 10:11:27","doi":"10.21203/rs.3.rs-4402479/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"communications-earth-and-environment","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"commsenv","sideBox":"Learn more about [Communications Earth and Environment](https://www.nature.com/commsenv/)","snPcode":"","submissionUrl":"","title":"Communications Earth \u0026 Environment","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Communications Series","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"53571e41-0b21-4da4-8543-b95d85205eed","owner":[],"postedDate":"August 5th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":33517218,"name":"Earth and environmental sciences/Climate sciences"},{"id":33517219,"name":"Earth and environmental sciences/Climate sciences/Climate change/Climate and Earth system modelling"},{"id":33517220,"name":"Earth and environmental sciences/Climate sciences/Climate change/Climate-change impacts"}],"tags":[],"updatedAt":"2024-08-05T10:11:28+00:00","versionOfRecord":[],"versionCreatedAt":"2024-08-05 10:11:27","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4402479","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4402479","identity":"rs-4402479","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}