The Arctic is warming four times faster than the rest of the world, raising the stakes of the climate crisis for the entire planet.
Scientific bodies like the US National Oceanic and Atmospheric Administration (NOAA) have previously said that the northern reaches of the planet are heating up twice as fast as other regions.
But the new results, published on Thursday in the journal Communications Earth & Environment, found that the Arctic as a whole has warmed much faster than that in the past four decades.
Global temperatures are rising due to human-caused greenhouse gas emissions, mainly from the use of fossil fuels.
The new research comes a day after staggering findings from the other side of the world. An international team of scientists published research on Wednesday that the East Antarctic Ice Sheet, known as the “sleeping giant”, could singlehandedly raise sea levels by up to five metres (16ft) in the next few centuries if planetary heating continues apace.
Sea level rise is also being driven by warming in the Arctic, which has helped melt the vast Greenland ice sheet – meaning warming temperatures at both poles could have serious ramifications globally.
The new study was started after a series of intense heatwaves in the Arctic in 2020, Mika Rantanen, a climate scientist at the Finnish Meteorological Institute and lead author, told The Independent this week.
Dr Rantanen and colleagues looked at Arctic warming from observed temperature data gathered between 1979 and 2021. Good satellite data, the key to studying the remote Arctic, first became available in 1979, he explained.
Since then, the Arctic as a whole has warmed 3.8 times as fast as the global average, the authors found.
The rate of warming wasn’t uniform across the Arctic. In general, areas closer to the North Pole warmed faster than areas further south, the study found.
Some specific locations have gotten hotter extremely quickly. For example, the area around Novaya Zemlya, a group of islands in northeast Russia, has been warming around seven times as fast as the global average.
As Arctic sea ice melts, so does the habitat of species including polar bears and walruses, threatening their survival. More heat in the Arctic is also devastating the once-permanently frozen ground, the tundra, and leaving communities facing erosion and flooding.
Then there’s the melting of Arctic ice sheets and glaciers which add to global sea level rise.
This speedier warming is a phenomenon known as “Arctic amplification”, and is partly due to melting sea ice, Dr Rantanen explained.
Sea ice melts over the summer, allowing heat from the ocean to rise into the atmosphere, Dr Rantanen says.
As sea ice melts, the darker colour of the open ocean absorbs more sunlight and heat than the brilliant, reflective quality of the ice, also helping to speed up warming.
In addition, Arctic warming is fuelled by the movement of air and moisture through the atmosphere, climate scientist Matthew Henry previously wrote in Carbon Brief.
The new study builds on other recent research that concluded that the Arctic is now warming even faster than previously thought. Another study from earlier this summer appeared to support the new findings, concluding that the Arctic had warmed around four times as fast as the world at times in the past two decades.
The paper notes that “earlier estimates may be outdated due to continued warming in the Arctic”, meaning new data has changed the estimated warming rate. It’s also possible that earlier studies assessed more area south of the Arctic Circle, Dr Rantanen said, where areas are warming more slowly than around the North Pole.
Nick Lutsko, a climate scientist at the Scripps Institution of Oceanography who was not involved in the research, told The Independent that he thought the new paper was “pretty thorough”.
“If Arctic amplification is really a factor of four, that’d be really bad news for everyone living in the Arctic Circle or near the Arctic Circle,” Dr Lutsko said.