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The Arctic is warming nearly four times faster than the Earth as a whole, new research shows. The results are a reminder that people, plants and animals in the polar regions are experiencing rapid and disastrous climate change.
Scientists have previously estimated that the Arctic is warming about twice as fast as the globe as a whole. The new study finds this to be a significant underestimate of recent warming. Over the past 43 years, the region has warmed 3.8 times faster than the planet as a whole, according to the authors.
The study focuses on the period between 1979, when reliable satellite measurements of global temperatures began, and 2021.
“The Arctic is more sensitive to global warming than previously thought,” says Mika Rantanen of the Finnish Meteorological Institute, who is one of the authors of the study published in the journal Earth & Environment Communications.
There have been hints in recent years that the Arctic is warming even faster than computer models predicted. Heat waves in the Far North have caused breathtaking wildfires and melting ice in the circumpolar region that includes Alaska, the Canadian Arctic, Greenland, Scandinavia and Siberia.
“It will probably be a bit of a surprise, but also a kind of extra motivation maybe,” says Richard Davy, a climatologist at the Nansen Environmental and Remote Sensing Center in Norway, who was not involved in the new study. “Things are moving faster than we would have expected based on the model’s projections.”
There are many reasons why the Arctic is warming faster than other parts of the Earth. Changes in the amount of air pollution from Europe and natural climate variations over several decades likely play a role. But human-caused global warming is the underlying reason for warming the Arctic and the planet as a whole.
Loss of sea ice is one of the most obvious drivers of Arctic warming. The Arctic Circle is primarily an ocean, which was once frozen for most or all of the year. But permanent sea ice is steadily shrinking, and seasonal ice is melting earlier in the year and re-forming later.
This means more open water. But while the ice is shiny and reflects the sun’s heat, the water is darker and absorbs it. This heat helps melt more ice, which means more water to trap more heat – the loop feeds on itself, accelerating warming in the Arctic.
“That’s why the temperature trends are the highest [in] areas where sea ice has shrunk the most,” says Rantanen. There are hotspots in the Bering Sea above northern Europe and Siberia, which are warming about seven times faster than the global average, the study finds.
The rapid warming of the Arctic affects people living far from the Arctic Circle. For example, there is evidence that weather patterns change in the United States and Europe as sea ice melts, and many marine species migrate between the tropics and the Arctic each year. “What happens in the Arctic doesn’t just stay in the Arctic,” says Davy.
The new research also reveals that the advanced computer models that scientists use to understand how the global climate is changing now and will change in the future are struggling to capture the relative rate of warming in the Arctic. This suggests that future models may need to be adjusted to better capture the realities of global warming in polar regions, although this study did not reveal what exactly current models are missing.
“The paper’s conclusion that climate models tend to underestimate the rate of warming [between the Arctic and the Earth as a whole] is really interesting,” says Kyle Armour, a climatologist at the University of Washington who was not involved in the new study.
Previous studies have shown that computer models actually do a good job of estimating how much the Arctic has warmed, but tend to overestimate how much warmer the entire planet is, Armor says. This means that the model comparison between Arctic warming and global warming ends up being incorrect.
“We still have work to do to determine the source of this model bias,” Armor says. And that work is increasingly important as world leaders use climate models to understand what the future holds and how to avoid even more catastrophic warming.