Striking study finds Arctic Circle warming at 4 times the global rate
Scientists understand the area in and around the North Pole to be warming disproportionately to the rest of the planet, a phenomenon known as "Arctic amplification." A new study, however, argues that this effect has been vastly underestimated, concluding that the rate of warming occurring in the Arctic Circle is happening around four times faster than the global average.
Arctic amplification is driven in large part by the loss of sea ice and snow that bounces sunlight back into space, a feedback loop that accelerates the local rate of warming. How much more this is causing the Arctic to heat up as compared to the rest of the globe is a matter of conjecture, but it is generally estimated it to be around two to three times.
Scientists at the Finnish Meteorological Institute say this is a significant underestimation, and in their newly published paper argue the actual rate is 3.8. The researchers say previous estimates have been plagued by imprecise boundaries around what is considered "the Arctic," insufficient timeframes, and unreliable data. To address this, the team drew clear lines around the Arctic Circle, tapped into solid new satellite data from 1979 to 2021, and came to what they consider a more accurate conclusion.
“The Arctic was defined using the Arctic Circle because we wanted to use an area which most people perceive as the Arctic," explained lead author Mika Rantanen." We focused on a period that began in 1979 because the observations after that year are more reliable and because strong warming began in the 1970s."
According to the scientists, parts of the Arctic even warmed at up to seven times the global rate during that period. They attempted to match their calculations up with current climate models and found they struggled to simulate the fourfold warming rate, only reinforcing the idea that Arctic amplification is currently being underestimated.
“While the magnitude of Arctic amplification is dependent to some degree on how the Arctic region is defined, and by the period of time used in the calculation, the climate models were found to underestimate Arctic amplification almost independent of the definition,” Rantanen explained.
While the consensus around Arctic amplification has generally pinned the rate at two to three times the global average, scientists have recently started to suggest it may be higher. In "contrast to the widely-held conventional wisdom," NASA scientists presenting at the American Geophysical Union last year also put the figure at four, pointing to many of the same shortcomings with previous research.
As the warming trend continues and more data comes into view, these observation will only become clearer, which bodes ominously for the northernmost region of our planet.
The research was published in the journal Communications Earth & Environment.
Source: Finnish Meteorological Institute