Sea ice reflects sunlight well, but melts. This allows the darker ocean below to absorb more energy. The loss of Molsok ice also means that it no longer limits the ability of warmer sea waters to warm Arctic air. The more ice is lost, the more heat accumulates, forming a feedback loop.
“We expected to see a lot of warming, but not on the scale that we found,” said Ketil Isaken, a senior scientist at the Norwegian Meteorological Institute who led the work. “We were all surprised. From what we know from every other observation point on the globe, this is the highest rate of warming we have seen so far.”
“The broader message is that the feedback from sea ice melt is even higher than previously shown,” he said. “This is an early warning of what will happen across the Arctic if this melting continues, and what is likely to happen in the coming decades.” In April, scientists around the world said urgent and deep cuts in carbon and other greenhouse gas emissions were needed to resolve the climate emergency.
“This study shows that even the best possible models underestimate the rate of warming in the Barents Sea,” said Dr Ruth Mottram, a climatologist at the Danish Meteorological Institute, who is not part of the group. “We seem to be seeing it transition into a new regime as it becomes less like the Arctic and more like the North Atlantic. The situation is really on edge right now and it is unlikely that sea ice will persist in this region for much longer.”
The study, published by Scientific Reports, is based on data from automatic weather stations on the islands of Svalbard and Franz Josef Land. Until that time, it had not gone through the standard quality control process and was not published.
The result is a high-quality set of surface air temperature measurements from 1981 to 2020. The researchers concluded: “Regional warming rates for the northern part of the Barents Sea are unusual and correspond to average warming in the Arctic 2-2.5 times greater than the average for the Arctic, and 5-7 times higher than global warming.”< /p>
There was a very strong time correlation between air temperature, sea ice loss and ocean temperature. Isaken said that the rapid rise in air temperature would have a significant impact on ecosystems: “For example, here in Oslo, the temperature rises by 0.4°C per decade, and people really feel the disappearance of snow in winter. But what is happening in the North is going through the roof.”
Isaken noted that new information about the rate of heating in the area will help other scientists investigate how changes in the Arctic affect extreme weather in densely populated areas at lower latitudes. There is evidence that rapid heating is changing the flow winds that surround the pole and affect extreme weather.”
“Loss of sea ice and warming in the Barents Sea, in particular, have been highlighted in previous work as having of particular importance for changes in atmospheric circulation in winter, when associated with extreme winter weather events,” said Professor Michael Mann from Pennsylvania State University, USA. “If this mechanism really works, and this is still being argued, then this , by which climate change could lead to an increase in certain types of extreme weather that are poorly captured in current models.”
