A High‐End Estimate of Sea Level Rise for Practitioners

Earth s Future, Год журнала: 2022, Номер 10(11)

Опубликована: Окт. 23, 2022

Sea level rise (SLR) is a long-lasting consequence of climate change because global anthropogenic warming takes centuries to millennia equilibrate for the deep ocean and ice sheets. SLR projections based on models support policy analysis, risk assessment adaptation planning today, despite their large uncertainties. The central range distribution estimated by process-based models. However, risk-averse practitioners often require information about plausible future conditions that lie in tails distribution, which are poorly defined existing Here, community effort combining scientists builds framework discussing physical evidence quantify high-end practitioners. approach complementary IPCC AR6 report provides further physically scenarios. High-end estimates different components developed two scenarios at timescales. For +2°C 2100 (RCP2.6/SSP1-2.6) relative pre-industrial values our up 0.9 m 2.5 2300. Similarly, (RCP8.5/SSP5-8.5), we estimate 1.6 10.4 growing differences between beyond emphasize long-term benefits mitigation. even modest 2°C may cause multi-meter centennial time scales with profound consequences coastal areas. Earlier assessments focused instability mechanisms Antarctica, while here importance timing shelf collapse around Antarctica. This highly uncertain due low understanding driving processes. Hence both process emission scenario control SLR.

Язык: Английский

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Mechanisms and Impacts of Earth System Tipping Elements

Reviews of Geophysics, Год журнала: 2023, Номер 61(1)

Опубликована: Фев. 16, 2023

Abstract Tipping elements are components of the Earth system which may respond nonlinearly to anthropogenic climate change by transitioning toward substantially different long‐term states upon passing key thresholds or “tipping points.” In some cases, such changes could produce additional greenhouse gas emissions radiative forcing that compound global warming. Improved understanding tipping is important for predicting future risks and their impacts. Here we review mechanisms, predictions, impacts, knowledge gaps associated with 10 notable proposed be elements. We evaluate approaching critical whether shifts manifest rapidly over longer timescales. Some have a higher risk crossing points under middle‐of‐the‐road pathways will possibly affect major ecosystems, patterns, and/or carbon cycling within 21st century. However, literature assessing scenarios indicates strong potential reduce impacts many through mitigation. The studies synthesized in our suggest most do not possess abrupt years, exhibit behavior, rather responding more predictably directly magnitude forcing. Nevertheless, uncertainties remain elements, highlighting an acute need further research modeling better constrain risks.

Язык: Английский

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Deglaciation of northwestern Greenland during Marine Isotope Stage 11

Science, Год журнала: 2023, Номер 381(6655), С. 330 - 335

Опубликована: Июль 20, 2023

Past interglacial climates with smaller ice sheets offer analogs for sheet response to future warming and contributions sea level rise; however, well-dated geologic records from formerly ice-free areas are rare. Here we report that subglacial sediment the Camp Century core preserves direct evidence northwestern Greenland was free during Marine Isotope Stage (MIS) 11 interglacial. Luminescence dating shows just beneath deposited by flowing water in an environment 416 ± 38 thousand years ago. Provenance analyses cosmogenic nuclide data calculations suggest reworked local materials exposed at surface <16 before deposition. Ice modeling indicates conditions require least 1.4 meters of equivalent contribution Sheet.

Язык: Английский

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The World Atlas of Last Interglacial Shorelines (version 1.0)

Earth system science data, Год журнала: 2023, Номер 15(1), С. 1 - 23

Опубликована: Янв. 3, 2023

Abstract. This paper presents version 1.0 of the World Atlas Last Interglacial Shorelines (WALIS), a global database sea-level proxies and samples dated to marine isotope stage 5 (∼ 80 130 ka). The includes series datasets compiled in framework special issue published this journal (https://essd.copernicus.org/articles/special_issue1055.html, last access: 15 December 2022). collates individual contributions (archived Zenodo community at https://zenodo.org/communities/walis_database/, 2022) into an open-access, standalone (Rovere et al., 2022, https://doi.org/10.5281/zenodo.7348242). release WALIS complete documentation scripts download, analyze, visualize data (https://alerovere.github.io/WALIS/, contains 4545 (e.g., terraces or fossil beach deposits), 4110 corals with U-series), 280 other time constraints biostratigraphic tephra layers) interconnected several tables containing accessory metadata. By creating centralized proxy for Interglacial, will be valuable resource broader paleoclimate facilitate data–model integration intercomparisons, assessments reconstructions between different studies regions, as well comparisons past history data.

Язык: Английский

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The Ronne Ice Shelf survived the last interglacial

Nature, Год журнала: 2025, Номер 638(8049), С. 133 - 137

Опубликована: Янв. 29, 2025

Abstract The fate of the West Antarctic Ice Sheet (WAIS) 1 is largest cause uncertainty in long-term sea-level projections. In last interglacial (LIG) around 125,000 years ago, data suggest that sea level was several metres higher than today 2–4 , and required a significant contribution from ice loss, with WAIS usually implicated. Antarctica Southern Ocean were warmer 5–8 by amounts comparable to those expected 2100 under moderate high future warming scenarios. However, direct evidence about size LIG sparse. Here we use salt an core Skytrain Rise, adjacent WAIS, show that, during most LIG, Ronne Shelf still place, close its current extent. Water isotope are consistent retreat 9 but seem inconsistent more dramatic model realizations 10 which both large shelves lost. This new constraint calls for reappraisal other elements budget. It also weakens observational basis motivated simulations projecting highest end projections rates rise 2300 beyond.

Язык: Английский

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Rapid northern hemisphere ice sheet melting during the penultimate deglaciation

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Июль 2, 2022

Abstract The rate and consequences of future high latitude ice sheet retreat remain a major concern given ongoing anthropogenic warming. Here, new precisely dated stalagmite data from NW Iberia provide the first direct, high-resolution records periods rapid melting Northern Hemisphere sheets during penultimate deglaciation. These reveal deglaciation initiated with century-scale meltwater pulses which subsequently trigger abrupt coolings air temperature in consistent freshwater-induced AMOC slowdowns. these slowdowns, 600-year duration, was shorter than Heinrich 1 last Although similar insolation forcing two deglaciations, more sustained freshening eastern North Atlantic likely reflects larger volume stored marine-based Eurasian Ice glacial contrast to land-based on America as glacial.

Язык: Английский

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Megafauna diversity and functional declines in Europe from the Last Interglacial to the present

Global Ecology and Biogeography, Год журнала: 2023, Номер 33(1), С. 34 - 47

Опубликована: Ноя. 17, 2023

Abstract Aim Reconstructing megafauna diversity in the past before anthropogenic impacts is crucial for developing targeted restoration strategies. We estimated and functional decline of European present compared with nearest in‐time climate period analogue to but prior worldwide diffusion Homo sapiens. Location Europe. Time Period Last Interglacial (LIG; ca. 127,000 years ago) present. Major Taxa Studied Wild, large (≥10 kg) terrestrial mammals. Methods assessed distribution 48 species during LIG using hindcasting modelling fossil records. Then, we community potential trait‐based effects from present, accounting differences between two periods. Results Species richness biomass dropped by 70.8% (±11.7%) 94.5% (±9.9%). Functional 80.3% (±15.3%) herbivores 64.9% (±29.1%) carnivores, while trait‐informed vegetation meat consumptions 82.3% (±13.4%) 60.5% (±26.0%). The loss associated ecological processes were high everywhere, particularly western Europe carnivores East Plain herbivores. Potential periods was similar if only climate‐driven considered. Main Conclusions Severe, size‐biased defaunation has degraded assemblages megafauna‐mediated across These patterns cannot be explained periods, thus likely driven prehistoric results suggest that structure wild ecosystems strongly deviates evolutionary norm, decreased heterogeneity fluxes biogeochemical compounds trophic networks, highlighting importance ambitious policies support ecosystem functioning.

Язык: Английский

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Constraining the contribution of the Antarctic Ice Sheet to Last Interglacial sea level

Science Advances, Год журнала: 2023, Номер 9(27)

Опубликована: Июль 5, 2023

Polar temperatures during the Last Interglacial [LIG; ~129 to 116 thousand years (ka)] were warmer than today, making this time period an important testing ground better understand how ice sheets respond warming. However, it remains debated much and when Antarctic Greenland changed period. Here, we present a combination of new existing absolutely dated LIG sea-level observations from Britain, France, Denmark. Because glacial isostatic adjustment (GIA), melt contribution change in region is small, which allows us constrain change. We find that global mean sea level peaked early interglacial (before 126 ka), with maximum 5.7 m (50th percentile, 3.6 8.7 central 68% probability) before declining. Our results support asynchronous history over LIG, followed by later Ice Sheet mass loss.

Язык: Английский

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The future extent of the Anthropocene epoch: A synthesis

Global and Planetary Change, Год журнала: 2024, Номер unknown, С. 104568 - 104568

Опубликована: Сен. 1, 2024

Язык: Английский

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Last Interglacial subsurface warming on the Antarctic shelf triggered by reduced deep-ocean convection

Communications Earth & Environment, Год журнала: 2024, Номер 5(1)

Опубликована: Апрель 20, 2024

Abstract The Antarctic ice-sheet could have contributed 3 to 5 m sea-level equivalent the Last Interglacial highstand. Such an ice-mass loss compared pre-industrial requires a subsurface warming on shelf of ~ °C according modelling studies. Here we show that substantial is simulated south 60 °S in equilibrium experiment Interglacial. It averages +1.2 at 500 depth from 70 °W 160 °E, and it reaches +2.4 near Lazarev Sea. Weaker deep-ocean convection due reduced sea-ice formation primary driver this warming. associated changes meridional density gradients surface winds lead weakened Circumpolar Current strengthened Slope Current, which further impact temperatures. A trigger can thus be obtained during warm periods formation.

Язык: Английский

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