Multimodel Study - Blue Ocean Arctic During Summers Now "Highly Likely" Before 2050, Even W. C Cuts
The loss of summer sea ice in the Arctic is now very likely before 2050, new research shows, even if the carbon emissions driving the climate crisis are cut rapidly. The result has alarmed scientists but they said slashing greenhouse gases remained vital as this would determine whether Arctic summer ice vanished permanently or could recover over time. If emissions remain very high, there is a risk the Arctic could be ice-free even in the dark, cold winter months, a possibility described as “catastrophic”.
The last global scientific assessment of Arctic ice was in 2013. It predicted a complete loss of ice in the month of September, when it reaches its annual minimum, would occur only if CO2 emissions from human activities remained high. The new results are based on 40 of the latest computer models and is the best assessment to date of the fate of the Arctic ice. Since satellite records began in 1979, summer Arctic ice has lost 40% of its area and up to 70% of its volume, making it one of the clearest signs of human-caused global heating. In 2019, it shrank to its second lowest extent on record.
The loss of the ice exposes the dark ocean, which absorbs more of the sun’s heat and further ramps up temperatures. These changes are also being increasingly linked to more extreme weather including severe winters, deadly summer heatwaves and torrential floods at lower latitudes such as in Europe and the US.
“Alarmingly the models repeatedly show the potential for ice-free summers in the Arctic Ocean before 2050, almost irrespective of the measures taken to mitigate the effects of climate change,” said Ed Blockley, who leads the UK Met Office’s polar climate programme and was one of the team behind the new research. “The signal is there in all possible futures. This was unexpected and is extremely worrying.” Prof Dirk Notz, at the University of Hamburg, Germany, coordinated the analysis and said: “If we keep global warming below 2C, Arctic sea ice will nevertheless likely disappear occasionally in summer even before 2050. This really surprised us.”
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https://www.theguardian.com/world/2020/apr/21/ice-free-arctic-summers-now-very-likely-even-with-climate-action
