The polar regions in a 2°C warmer world

Science Advances, Journal Year: 2019, Volume and Issue: 5(12)

Published: Dec. 5, 2019

Over the past decade, Arctic has warmed by 0.75°C, far outpacing global average, while Antarctic temperatures have remained comparatively stable. As Earth approaches 2°C warming, and may reach 4°C mean annual 7°C 3°C winter respectively. Expected consequences of increased warming include ongoing loss land sea ice, threats to wildlife traditional human livelihoods, methane emissions, extreme weather at lower latitudes. With low biodiversity, ecosystems be vulnerable state shifts species invasions. Land ice in both regions will contribute substantially level rise, with up 3 m rise possible if certain thresholds are crossed. Mitigation efforts can slow or reduce but without them northern high latitude accelerate next two four decades. International cooperation crucial foreseeing adapting expected changes.

Language: Английский

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Arctic sea ice trends, variability and implications for seasonal ice forecasting

Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences, Journal Year: 2015, Volume and Issue: 373(2045), P. 20140159 - 20140159

Published: June 2, 2015

September Arctic sea ice extent over the period of satellite observations has a strong downward trend, accompanied by pronounced interannual variability with detrended 1 year lag autocorrelation essentially zero. We argue that through combination thinning and associated processes related to warming climate (a stronger albedo feedback, longer melt season, lack especially cold winters) trend itself is steepening. The manifests both inherent large in summer atmospheric circulation patterns oceanic heat loss winter acts as negative (stabilizing) albeit insufficient counter steepening trend. These findings have implications for seasonal forecasting. In particular, while advances observing thickness assimilating into coupled forecast systems improved skill, there remains an limit predictability owing largely chaotic nature variability.

Language: Английский

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Southern Ocean Phytoplankton in a Changing Climate

Frontiers in Marine Science, Journal Year: 2017, Volume and Issue: 4

Published: Feb. 16, 2017

Phytoplankton are the base of Antarctic food web, sustain wealth and diversity life for which Antarctica is renowned, play a critical role in biogeochemical cycles that mediate global climate. Over vast expanse Southern Ocean (SO), climate variously predicted to experience increased warming, strengthening wind, acidification, shallowing mixed layer depths, light (and UV), changes upwelling nutrient replenishment, declining sea ice, reduced salinity, southward migration ocean fronts. These expected alter structure function phytoplankton communities SO. The diverse environments contained within SO will be impacted differently by change; causing identity magnitude environmental factors driving biotic change vary among bioregions. Predicting net effect multiple climate-induced stressors over range complex. Yet understanding response vital if we predict future state/s ecosystem, estimate impacts on fisheries endangered species, accurately effects physical This review looks at major define SO, examines forecast environment, predicts likely these phytoplankton, considers ramifications trophodynamics feedbacks change. Predictions strongly suggest all regions productivity community composition with nature, even sign, varies depend upon sequence imposed. It affect biogeochemistry, carbon export, nutrition higher trophic levels.

Language: Английский

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Climate trends in the Arctic as observed from space

Wiley Interdisciplinary Reviews Climate Change, Journal Year: 2014, Volume and Issue: 5(3), P. 389 - 409

Published: March 11, 2014

The Arctic is a region in transformation. Warming the has been amplified, as expected from ice‐albedo feedback effects, with rate of warming observed to be ∼0.60 ± 0.07°C/decade (>64°N) compared ∼0.17°C/decade globally during last three decades. This increase surface temperature manifested all components cryosphere. In particular, sea ice extent declining at ∼3.8%/decade, whereas perennial (represented by summer minimum) much greater ∼11.5%/decade. Spring snow cover also −2.12%/decade for period 1967–2012. Greenland sheet losing mass ∼34.0 Gt/year (sea level equivalence 0.09 mm/year) 1992 2011, but 2002–2011, higher loss ∼215 observed. Also, glaciers worldwide declined 226 1971 2009 and 275 1993 2009. Increases permafrost have measured many parts Northern Hemisphere while thickening active layer that overlies thinning seasonally frozen ground reported. To gain insight into these changes, comparative analysis trends clouds, albedo, Oscillation presented. article categorized under: Paleoclimates Current Trends > Modern Climate Change

Language: Английский

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The urgency of Arctic change

Polar Science, Journal Year: 2018, Volume and Issue: 21, P. 6 - 13

Published: Nov. 27, 2018

This article provides a synthesis of the latest observational trends and projections for future Arctic. First, Arctic is already changing rapidly as result climate change. Contemporary warm temperatures large sea ice deficits (75% volume loss) demonstrate states outside previous experience. Modeled changes cryosphere that even limiting global temperature increases to near 2 °C will leave much different environment by mid-century with less snow ice, melted permafrost, altered ecosystems, projected annual mean increase +4 °C. Second, under ambitious emission reduction scenarios, high-latitude land melt, including Greenland, are foreseen continue due internal lags, leading accelerating level rise throughout century. Third, may in turn impact lower latitudes through tundra greenhouse gas release shifts ocean atmospheric circulation. Arctic-specific radiative heat storage feedbacks become an obstacle achieving stabilized climate. In light these trends, precautionary principle calls early adaptation mitigation actions.

Language: Английский

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