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Since the 1990s, warming has been twice as fast in the Arctic as in the rest of the world
COPENHAGEN – Sea ice in the Arctic was at record lows for October, as unusually warm waters slowed ice recovery, Danish researchers said Wednesday.
The decrease in sea ice is a reminder of how the Arctic is particularly affected by global warming.
Since the 1990s, warming has been twice as fast in the Arctic as in the rest of the world, as a phenomenon dubbed “Arctic amplification” causes air, ice and water to interact in a reinforcing way.
“Arctic sea ice extent in October will be the lowest ever recorded and sea ice growth rate is slower than normal,” Rasmus Tonboe, a scientist at the Danish Meteorological Institute (DMI), told AFP. that the record has not been equal for at least 40 years.
According to preliminary satellite data used by the institute, the sea ice surface was 6.5 million square kilometers (2.5 million square miles) on October 27.
Each year, some of the ice that forms in Arctic waters melts in the summer.
It usually reaches a low point of around five million square kilometers, but then reforms to cover around 15 million square kilometers in winter. Warmer temperatures are now reducing the extent of both summer and winter ice.
Satellite data has been collected to monitor ice since 1979, and the downward trend is clear.
For the month of October, the measurements show a downward trend of 8.2% in the ice over the past 10 years.
As early as September, researchers noted the second lowest extent of sea ice recorded in the Arctic, although it didn’t quite reach the low levels recorded in 2012.
But warmer-than-normal seawater slowed new ice formation in October.
– ‘Vicious spiral’ –
The water temperature in the eastern arctic, north of Siberia, was two to four degrees warmer than normal, and in Baffin Bay it was one to two degrees warmer, DMI said in a statement.
The institute said this was following a trend observed in recent years which has been described as a “vicious spiral”.
“It’s a trend we’ve seen in recent years, with a longer open water season warming the sea for a longer period, resulting in shorter winters so the ice doesn’t grow as thick as it used to.” Tonboe said.
Since the melting ice is already in the ocean, it does not directly contribute to sea level rise.
But when the ice disappears, the sunlight “is absorbed by the ocean, helping to further warm the Earth,” Claire Parkinson, a NASA climate scientist, told AFP in September.
Therefore, with less ice reflecting sunlight, the oceans are heated directly.
Over the past 40 years the Arctic has also become a strategic interest for world powers.
Less ice in some areas has opened up new sea routes, which are set to play a more important role in international trade, which means greater financial participation for Arctic state actors.
It is estimated that the region will also host 13% of the world’s oil reserves and 30% of undiscovered natural gas fields.
Potsdam’s German Institute for Climate Impact Research (PIK) said Tuesday that with current levels of atmospheric CO2 – around 400 parts per million – melting Arctic sea ice would increase global temperatures by 0.2 ° C. .
In addition to 1.5 ° C of warming, our current levels of emissions have made it almost inevitable and the safest limit to global warming under the Paris climate agreement.
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