Arctic: summers without sea ice likely from 2030

Researchers are concerned that the Arctic will be deprived of its sea ice in summer from the 2030s. A direct consequence of greenhouse gas emissions.

By VD with AFP

The Arctic Ocean covers an area of ​​approximately 14 million square kilometers and is covered in ice for most of the year.
© PHILIPPE ROY / Philippe ROY / Aurimages via AFP

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I’The Arctic could be sea ice-free in summer as early as the 2030s, much sooner than previously estimated, and even under a low greenhouse gas emissions scenario, researchers say in a paper published on Tuesday. . Scientists based in Korea, Canada and Germany used observation data from the years 1979-2019 to run new simulations. “The results indicate that the first month of September without sea ice will occur as early as the years 2030-2050, regardless of the emission scenarios,” they conclude in the review. NatureCommunications.

When the experts speak of the absence of ice, this means an area of ​​less than 1 million square kilometers, because there may always be residual ice along the coasts. The Arctic Ocean covers an area of ​​approximately 14 million square kilometers and is covered in ice for most of the year. September is the month in which the ice usually reaches its annual minimum.

Advanced forecasts

“This is about a decade earlier than recent projections by the IPCC”, the group of climate experts mandated by the UN, underlines Seung-Ki Min, of the South Korean universities of Pohang and Yonsei, co-author of the article. The researchers also believe that the decline of this ice can be attributed mainly to greenhouse gas emissions, the other factors (aerosols, solar and volcanic activity, etc.) being much less important.

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Sea ice, which forms the pack ice, is made of salt water on the surface of an ocean, which has frozen under the effect of the cold. Its melting does not directly cause a rise in the level of the oceans (contrary to that of the ice cap and glaciers), but nevertheless has harmful consequences. Indeed, this ice plays a very important role in summer, by returning the rays of the sun, which makes it possible to cool the Arctic. This mirror is now getting smaller and smaller, and the Arctic is therefore warming up much faster than other regions.

Acceleration of global warming

The disappearance of the ice “will accelerate Arctic warming, which can increase extreme weather events at mid-latitudes, such as heat waves and forest fires”, notes Seung-Ki Min. “It can also accelerate global warming, by melting permafrost, as well as sea level rise by melting the Greenland ice cap,” adds the researcher.

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“This will be the first major component of our climate system that we lose through our greenhouse gas emissions,” said Dirk Notz of the University of Hamburg, another co-author of the study. “Scientists have been warning about this disappearance for decades and it is sad to see that these warnings have for the most part not been heeded”, he regrets.

Dirk Notz now hopes that policymakers will pay heed to the researchers’ findings “so that we can at least protect the other components of our climate system, limiting future warming as much as possible.”

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