If the accelerated melting of the East Antarctic ice sheet, the world’s biggest, was discussed in these columns the same day last week, this week it is the turn of the Arctic. The latest alarming finding is that the pace of the temperature increase around the North Pole has been nearly four times faster than the globe since 1979. In a study published last Thursday, researchers at the Finnish Meteorological Institute cited a phenomenon known as Arctic amplification, caused by the heat-trapping emissions from burning fossil. 
Numerous studies have reported that the Arctic is warming either twice, more than twice, or even three times as fast as the globe on average. In the study in question, by using several observational datasets which cover the Arctic region, the researchers show that during the last 43 years, the Arctic has been warming nearly four times faster than the globe, which is a higher ratio than generally reported in literature. They compared the observed Arctic amplification ratio with the ratio simulated by state-of-the-art climate models, and found that the observed four-fold warming ratio over 1979-2021 is an extremely rare occasion in the climate model simulations. The observed and simulated amplification ratios are more consistent with each other if calculated over a longer period; however the comparison is obscured by observational uncertainties before 1979. The results indicate that the recent four-fold Arctic warming ratio is either an extremely unlikely event, or the climate models systematically tend to underestimate the amplification.
Climate models, which scientists used to predict long-term change, are not capturing this high rate of warming, according to lead author and researcher Mika Rantanen. This was part of the motivation for the study, published in the journal Communications Earth and Environment. By analysing temperature trends in the Arctic Circle between 1979 and 2021, the researchers found the rate of warming is particularly high in the Eurasian region of the Arctic, especially the Barents Sea, which has warmed seven times faster than the global average. Recent data revealed that the annual average temperature in the Barents region climbed by as much as 2.7 degrees Celsius each decade in the past 20 to 40 years, making the Barents Sea and its islands the fastest warming location on the planet.
Vanishing snow and ice, particularly sea ice, are one big reason why Arctic warming is on hyperspeed. The bright white snow and ice create a reflective shield that bounces incoming radiation from the sun back into space. But open ocean waters or bare rocks absorb that heat, raising the temperature. Last year’s annual Arctic Report Card, published by the National Oceanic and Atmospheric Administration, US, found that the Arctic region is warming faster than the rest of the Earth and is rapidly losing ice cover, transforming the typically frozen landscape to a greener and browner one than it was just roughly a decade ago.
All these findings also reflect the most recent UN state-of-the-science report on the climate crisis, which found the Arctic will continue to warm faster than the rest of the planet as long as humans continue to burn fossil fuels and release greenhouse gases into the atmosphere. “The Arctic is really more sensitive to global warming than previously thought,” Rantanen said. “Only time will tell. Let’s see how this will evolve in the future.”


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