Polar Bear in the Canadian Arctic
Photo: David Goldman/AP
According to a new study, the temperature in the Arctic has risen almost four times as fast as the global average in the past 40 years.
The Arctic is warming on average by 0.75 degrees per decade, according to a study by scientists from Norway and Finland published in the journal Communications Earth & Environment.
Previous climate models assumed a much slower rise in temperature.
For example, a report by the Intergovernmental Panel on Climate Change (IPCC) from 2019 stated that warming is progressing around twice as fast as the global average.
The scientists from Norway and Finland now examined four temperature data sets that have been collected by satellite in the Arctic since 1979.
They found that the warming is progressing even faster.
The experts have measured the highest rates of warming near the Russian twin island of Novaya Zemlya in the Arctic Ocean.
The environment there is warming up to seven times faster than the global average.
According to the study, one of the reasons for this is the reduced ice cover in winter.
In addition, the altered atmospheric circulation would have transported warmer air currents to the Arctic.
The results were "somewhat surprising" because they were so much higher than previous data, said co-author Antti Lipponen of the Finnish Meteorological Institute.
He spoke out in favor of putting the climate models to the test.
The albedo effect can have global consequences
The main reason for the rapid warming is a phenomenon called "Arctic amplification."
When ice and snow, which normally reflect sunlight, melt into seawater, there is an amplifying effect as the dark water absorbs heat from the sunlight and warms.
As a result, even more ice thaws or it only freezes with a delay in autumn, and the darker surface increases.
With such positive feedback, the impact of an event—in this case, global warming—is amplified.
This effect can be observed not only in the Arctic, but also in other polar regions and in mountains where the glaciers are melting.
The strong warming of the Arctic has global consequences.
In particular, scientists warn of a melting of the Greenland ice sheet, which could result in a rise in sea levels of around six meters.
"Climate change is man-made," said Lipponen.
"Something is happening in the Arctic and it will affect us all."