Global warming is happening far faster in the Arctic than previously believed, according to a new study by scientists at the Finnish Meteorological Institute in Helsinki.
The study shows that the Arctic has warmed nearly four times faster than the global average over the past 43 years. Some areas in the Arctic Ocean have even warmed up to seven times faster than the entire planet, the scientists write in the Communications Earth & Environment journal.
Climate models have underestimated this so-called "Arctic amplification," says lead author Mika Rantanen.
Until recently, the Arctic was always said to be warming twice as fast as the rest. However, an Arctic Council working group based in Tromsø, Norway, the Intergovernmental Forum for Cooperation and Coordination for the Arctic, reported as early as May 2021 that the increase in average surface temperatures in the Arctic between 1971 and 2019 was 3.1 degrees Celsius, about three times the global average.
Why is the Finnish researchers' estimate even higher? On one hand, they point to the strong, ongoing warming of the Arctic, but their definition of the Arctic and their calculation period are also different.
They define the Arctic as the entire zone located within the Northern Arctic Circle. They also calculate the magnitude of the warming from 1979, the first year that detailed and therefore reliable satellite data were available.
The Arctic amplification over the past 43 years, according to the Finnish researchers, has been influenced both by human-induced climate change - greenhouse gas emissions - and by natural long-term climate fluctuations.