Disappearing landscapes: The Arctic at +2.7°C global warming

Science, Год журнала: 2025, Номер 387(6734), С. 616 - 621

Опубликована: Фев. 6, 2025

Under current nationally determined contributions (NDCs) to mitigate greenhouse gas emissions, global warming is projected reach 2.7°C above preindustrial levels. In this review, we show that at such a level of warming, the Arctic would be transformed beyond contemporary recognition: Virtually every day year have air temperatures higher than extremes, Ocean essentially ice free for several months in summer, area Greenland reaches melting least month roughly quadruple, and permafrost half what it was times. These geophysical changes go along with widespread ecosystem disruptions infrastructure damage, which, as here, could substantially reduced by increased efforts limit warming.

Язык: Английский

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Uncertainties originating from GCM downscaling and bias correction with application to the MIS-11c Greenland Ice Sheet

Climate of the past, Год журнала: 2024, Номер 20(2), С. 281 - 296

Опубликована: Фев. 6, 2024

Abstract. The Marine Isotope Stage 11c (MIS-11c) interglacial is an enigmatic period characterized by a long duration of relatively weak insolation forcing, but it thought to have been coincident with large global sea-level rise 6–13 m. configuration the Greenland Ice Sheet during MIS-11c highstand therefore great interest. Given constraints limited data, model-based analysis may be use only if model uncertainties are adequately accounted for. A particularly under-addressed issue in coupled climate and ice-sheet modeling coupling surface air temperatures ice model. Many studies apply uniform “lapse rate” accounting for temperature differences at different altitudes over surface, this uniformity neglects both regional seasonal near-surface dependencies on altitude. Herein we provide first such that addresses these comparing one-way Community Earth System Model (CESM) results from several downscaling methodologies. In our study, spatially temporally varying method produced greatest success rate matching paleodata, suggests peak volume loss approximately 50 % compared present day (∼ 3.9 m contribution rise). This result lower bound existing data- studies, partly as consequence applied methodology some feedbacks. Additional examined two present-day analyses bias correction precipitation, spread initialization states times, spatial configurations precipitation corrections. No other factor exhibited greater influence simulated sheet than choice scheme.

Язык: Английский

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Geologic Provinces Beneath the Greenland Ice Sheet Constrained by Geophysical Data Synthesis

Geophysical Research Letters, Год журнала: 2024, Номер 51(8)

Опубликована: Апрель 16, 2024

Abstract Present understanding of Greenland's subglacial geology is derived mostly from interpolation geologic mapping its ice‐free margins and unconstrained by geophysical data. Here we refine the extent provinces synthesizing constraints on seismic, gravity, magnetic topographic North 72°N, no province clearly extends across whole island, leaving three distinct regions yet to be reconciled with margin geology. Geophysically coherent anomalies apparent boundaries are adjacent onset faster ice flow at both Petermann Glacier Northeast Greenland Ice Stream. Separately, based their subaerial expression, dozens unusually long, straight sub‐parallel valleys cross interior not resolved current syntheses topography.

Язык: Английский

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Sustained North Atlantic warming drove anomalously intense MIS 11c interglacial

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Июль 15, 2024

The Marine Isotope Stage (MIS) 11c interglacial and its preceding glacial termination represent an enigmatically intense climate response to relatively weak insolation forcing. So far, a lack of radiometric age control has confounded detailed assessment the insolation-climate relationship during this period. Here, we present

Язык: Английский

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Expedition 400 summary

Proceedings of the International Ocean Discovery Program. Expedition reports, Год журнала: 2025, Номер unknown

Опубликована: Март 24, 2025

Язык: Английский

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81Kr dating of 1 kg Antarctic ice

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Май 12, 2025

Recovering earth's climate history from ice cores requires reliable dating of the ice. 81Kr is ideal for radiometric up to more than one million years, but isotope so rare that it has long been a challenge apply on where sample size limited. Here, we show 1-kg ice-core samples Taylor Glacier, Antarctica. This made possible by an advance in detection with all-optical realization Atom Trap Trace Analysis. The achieved sample-size reduction facilitates basal sections direct implications open questions paleoclimatology, such as evolution glaciers Tibetan Plateau or stability Greenland and West-Antarctic sheets.

Язык: Английский

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Warming of +1.5 °C is too high for polar ice sheets

Communications Earth & Environment, Год журнала: 2025, Номер 6(1)

Опубликована: Май 20, 2025

Язык: Английский

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Polar paleoenvironmental perspectives on modern climate change

PLOS Climate, Год журнала: 2024, Номер 3(1), С. e0000333 - e0000333

Опубликована: Янв. 10, 2024

Earth's polar regions are at the forefront of environmental and climatic change.One clear example is accelerating loss Arctic summer sea ice due to amplification from 1979 2021 [1].Declining leading unprecedented marine ecosystem changes [2], creating complex ecological consequences on food webs biodiversity.Warmer fresher ocean advection subarctic Pacific North Atlantic waters into Ocean supporting boreal species farther north, a process termed borealization [3].To prepare for future climate conditions, resource policy managers need information about that could occur.The geological record-lithological, physical, biological, chemical archives history-combined with geomorphological ice-core records (Fig 1) provide evidence how ocean, atmosphere biological systems have responded past changes.We highlight four key research topics where paleoclimate data can improve our understanding past, present, drivers change.

Язык: Английский

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Subglacial valleys preserved in the highlands of south and east Greenland record restricted ice extent during past warmer climates

˜The œcryosphere, Год журнала: 2024, Номер 18(3), С. 1467 - 1493

Опубликована: Март 28, 2024

Abstract. The Greenland Ice Sheet is a key contributor to contemporary global sea level rise, but its long-term history and response episodes of warming in Earth's geological past remain uncertain. terrain covered by the ice sheet comprises ∼ 79 % 1.1 land surface contains geomorphological records that may provide valuable insights into ice-sheet behaviour. Here we use morphology radio-echo sounding data identify ice-covered valleys within highlands southern eastern numerical modelling constrain climatological glaciological conditions responsible for valley incision. Our mapping reveals intricate subglacial networks with morphologies are indicative substantial glacial modification an inherited fluvial landscape, yet many these presently situated beneath cold-based, slow-moving (i.e. non-erosive) ice. We our simple model experiments infer incision likely occurred erosive mountain glaciers during one or more phases Greenland's when was restricted contribution barystatic up +7 m relative today. this primarily prior growth continental-scale sheet, most late Miocene (ca. 7–5 Ma) and/or Pliocene 3.6–2.6 Ma). findings therefore new data-based constraints on early extent dynamics can serve as boundary models regional palaeoclimate warm periods important analogues climate change 21st century beyond.

Язык: Английский

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Intensified global volcanism during Late Pleistocene glacial strength shift

Research Square (Research Square), Год журнала: 2024, Номер unknown

Опубликована: Март 8, 2024

Abstract Reduced ice volume during interglacials is thought to amplify volcanic activity because ice-mass removal depressurises magma chambers 1 . While this process has been detected on regional 2 and perhaps semi-global scales 3 , a lack of globally representative tephra production records leaves the global relationship between glacial-interglacial cycles volcanism uncertain. Here, we interrogate by using database visible layers in marine sediments 4 applying statistical sampling techniques develop record spanning past million years. We find that explosive intensified at about 420 400 thousand years ago (ka), coinciding with Marine Isotope Stage (MIS) 11 – warmest interglacial when sea level was approximately 10 m above present 5 Greenland largely ice-free 6 propose positive feedbacks icesheet ablation increased carbon dioxide (CO2) outgassing may explain warmth, turn, Mid-Brunhes transition which heralded warmer 7 Concurrently, observe shift more organised cycles, characterised higher intensity peaks, mirroring eccentricity forcing seen records. More pronounced ice-volcano stronger 400,000 years, crucial period hominin evolution 8

Язык: Английский

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