The Arctic has warmed nearly four times faster than the rest of the planet during the last 40 years, according to research published on Thursday that suggests climate models are underestimating the rate of polar heating.
“We present evidence that during 1979–2021 the Arctic has been warming nearly four times as fast as the entire globe,” the authors said in the study.
“Thus, we caution that referring to Arctic warming as to being twice as fast as the global warming, as frequently stated in literature, is a clear underestimation of the situation during the last 43 years since the start of the satellite observations.”
While there is a long-held consensus among scientists that the Arctic is warming quickly, estimates have varied according to the timeframe studied and the definition of what constitutes the geographic area of the Arctic.
An Arctic Council working group based in Troms, Norway, had reported in May 2021 that the increase in average Arctic surface temperature between 1971 and 2019 was 3.1 degrees Celsius (5.58 degree Fahrenheit), about three times higher than the global average.
“The take in the literature is that the Arctic is warming about twice as fast as the globe, so for me it was a bit surprising that ours was so much higher than the usual number,” Antti Lipponen, co-author from the Finnish Meteorological Institute, told the AFP news agency.
The study, published in the journal Communications Earth & Environment, found significant regional variations in warming rate within the Arctic circle.
For example, the Eurasian sector of the Arctic Ocean, near the Svalbard and Novaya Zemlya archipelagos, has warmed as much as 1.25C (2.25F) per decade – seven times faster than the rest of the world.
The team found that even state-of-the-art climate models predicted Arctic warming to be approximately one-third lower than what the observed data showed.
They said that this discrepancy may be due to previous modelled estimates being rendered out of date by continued Arctic modelling.
“Maybe the next step would be to take a look at the models and I would be really interested in seeing why the models do not reproduce what we see in observations and what impact that is having on future climate projections,” said Lipponen.
As well as profoundly impacting local communities and wildlife that rely on sea ice to hunt, intense warming in the Arctic will have worldwide repercussions.
The Greenland ice sheet, which recent studies warn may be approaching a melting “tipping point”, contains enough frozen water to lift Earth’s oceans some six metres.
“Climate change is caused by humans. As the Arctic warms up, its glaciers will melt and this will globally affect sea levels,” said Lipponen.
“Something is happening in the Arctic and it will affect us all.”