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Deep fritz 12 dl activation key free2/24/2024 ![]() ![]() This translates to an increase in the Arctic-mean coastal erosion rate by a factor of between 1.8 and 2.9 by the end of the century with respect to the historical period. We project the Arctic-mean coastal erosion rate to increase from 0.9 ± 0.4 m yr −1 during the historical period (1850–1950) to 1.6 ± 0.5, 2.0 ± 0.7 and 2.6 ± 0.8 m yr −1 by the end of the twenty-first century (2081–2100) in the context of anthropogenic climate change according to the socioeconomic pathway (SSP) scenarios SSP1-2.6, SSP2-4.5 and SSP5-8.5, respectively (Fig. We quantify the magnitude, timing and sensitivity of Arctic coastal erosion and its associated OC loss in the context of climate change. Our approach allows us to make twenty-first-century projections of coastal erosion at the pan-Arctic scale. Our model considers the main thermal and mechanical drivers of erosion as dynamical variables, represented by yearly-accumulated positive temperatures and significant wave heights, and constant ground-ice content from observations. We develop a semi-empirical Arctic coastal erosion model combining observations from the Arctic Coastal Dynamics (ACD) database 33, climate reanalyses, ESM and ocean surface wave simulations (see Methods for details). In this study, we present a novel approach to represent Arctic coastal erosion at the scales of modern ESMs. The scale mismatch between Arctic coastal erosion and modern ESMs requires the development of holistic models that account for the key large-scale processes to bridge this gap 30, 31, 32. Nonetheless, it has not been considered in climate projections so far. ![]() Arctic coastal erosion is one form of abrupt permafrost thaw 22 and is a relevant component of the Arctic carbon cycle 23, 30. Despite consistent improvements in the representation of permafrost dynamics 26, 27, the current generation of Earth system models (ESMs) does not account for abrupt permafrost thaw, which may cause projections of OC losses to be largely underestimated 28, 29. Arctic coastal erosion alone releases about as much OC as all the Arctic rivers combined 23, 24, fuelling about one-fifth of Arctic marine primary production 25. The thawing of permafrost globally releases organic carbon (OC) and increases atmospheric and oceanic greenhouse gas concentrations, feeding back to further warming 20, 21, 22, 23. To fill this gap, we present twenty-first-century projections of coastal erosion at the pan-Arctic scale. However, the extent of this increase is still unknown, as no projections of Arctic coastal erosion rates across the pan-Arctic scale are available. Consequently, Arctic coastal erosion rates are expected to increase in the coming decades. New regimes of surface waves are also projected in the Arctic Ocean and along the coast 17, 18, 19. Arctic sea ice decline has already exceeded natural variability 15, and summer ice-free conditions are projected by mid-twenty-first century 16. As for the future, Arctic surface air temperature is projected to exceed its natural range of variability within the next decades 15. The historical acceleration of erosion in the Arctic is linked with the observed decreasing sea-ice cover 2, 4, 11, and increasing air surface 12, 13 and permafrost temperatures 14. In the past decades, coastal retreat rates have increased throughout the Arctic, often by a factor of two or more 6, 7, 8, 9, 10. Sea-ice loss expands the fetch for waves 2, 3 and prolongs the open-water season, increasing the vulnerability of the Arctic coast to erosion 4, 5. Permafrost thaw and ground-ice melt lead to soil decohesion and slumping, while surface ocean waves mechanically abrade the Arctic coast 1. Similar content being viewed by othersĪrctic coastal erosion is caused by a combination of thermal and mechanical drivers. Our results will inform policymakers on coastal conservation and socioeconomic planning, and organic carbon flux projections lay out the path for future work to investigate the impact of Arctic coastal erosion on the changing Arctic Ocean, its role as a global carbon sink, and the permafrost–carbon feedback. We develop a simplified semi-empirical model to produce twenty-first-century pan-Arctic coastal erosion rate projections. ![]() The sensitivity of erosion to warming roughly doubles, reaching 0.4–0.8 m yr −1 ☌ −1 and 2.3–4.2 TgC yr −1 ☌ −1 by the end of the century. Here we project the Arctic-mean erosion rate to increase and very likely exceed its historical range of variability before the end of the century in a wide range of emission scenarios. ![]() However, the magnitude, timing and sensitivity of coastal erosion increase to global warming remain unknown. Arctic coastal erosion damages infrastructure, threatens coastal communities and releases organic carbon from permafrost. ![]()
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