Why do polar environments have an extreme climate

Climate changeThe Arctic is warming three times as fast as the world

3.1 degrees Celsius - that is the key figure given in the new climate report for the Arctic. That is how much the mean air temperature north of the Arctic Circle has risen in the last 50 years. As a result, the Arctic is warming three times as fast as the world as a whole - more than was previously believed and a new record! The American polar explorer Jason Box works for the Geological Survey of Denmark and Greenland and is the chief author of the new Arctic Report:

"We were surprised by a jump in temperature after 2004. Since then, the rate of warming in the Arctic has increased by another 30 percent. We now know from several studies what this acceleration is due to, especially more frequent and longer heat episodes in the winter months . "

(dpa / Sputnik / Igor Ageyenko) Polar regions - global warming could intensify zombie fires
Zombie fires are fires that overwinter under a thick blanket of snow. In Alaska they are only responsible for about one percent of the burned area, said climate researcher Rebecca Scholten in the Dlf. However, extreme fire years with many fires exacerbated the phenomenon.

No extreme cold waves since the turn of the millennium

Icy permafrost episodes seem to be becoming increasingly rare in the Arctic. Since the turn of the millennium, there have been practically no extreme cold waves that lasted longer than 14 days, according to the report. At most in some regions of Siberia. The Arctic Ocean has lost almost half of the ice it had 40 years ago. Ice and snow are also increasingly evaporating on land, most of it on Greenland, where glaciers are increasingly melting. This has a decisive effect on the temperatures in the Arctic. Sebastian Gerland, geophysicist at the Norwegian Polar Institute in Tromsö:

"In the Arctic we have snow and ice, which means that a lot of the sunlight that hits the earth is reflected here. If there is now less snow and sea ice in this region with a changed climate, then there will be less of the light and thus also reflected by the energy. And this can also lead to greater warming. "

More violent storms gnaw the coasts

Climate change is not only gnawing at the Arctic ice, but also at the land masses. In some places in Alaska, according to the report, five meters of coastline break away every year and plunge into the sea. This is also a consequence of the strong warming in the polar region, according to Jason Box:

"The sea ice is decreasing, storms are becoming more violent, and as a result the force of the waves on the coast increases. At the same time, the permafrost on land is thawing and becoming unstable."

The ice in Greenland and Antarctica is melting faster and faster (picture-alliance / dpa / Albert Nieboer) Ice in the Arctic is melting faster and faster
Gigantic ice masses will melt in the next few decades and thus raise the sea level. The contribution of Greenland glaciers could be three to four times as high as assumed, said polar researcher Ingo Sasgen in the Dlf.

When the Arctic soils thaw, it creates other environmental problems as well. Katrin Vorkamp deals with them intensively. The German geoecologist is doing research at Aarhus University in Denmark. She is also one of the group of authors of the new Arctic Report:

"In connection with climate change, we now see that pollutants that have accumulated in the ice or in permafrost soils are released again. In the Arctic, for example, we now have data on the entry of pollutants into Canadian lakes, where the permafrost soil thaws in the area. And there we see an increase in these pollutants in the fish. "

Thawing permafrost soil releases pollutants

This involves the toxic heavy metal mercury on the one hand, and so-called POPs on the other. These are long-lived pollutants that accumulate in the food chain, such as PCBs. Once widely used as technical oils, cancer toxins have long been globally outlawed:

"So far we have seen that the concentrations fall in the course of these international measures. And suddenly we see in some places that the concentrations rise again."

The Inuit are particularly affected. They still traditionally feed on fish, seals and other marine animals that accumulate environmental toxins:

"So it was found that the concentrations in the blood of the Inuit are the highest in the world. Much higher than in Europe, in North America, although we are closer to the sources of these pollutants there."

The outlook for the Arctic remains bleak. According to the climate models, it will warm up by at least another three degrees Celsius by the end of the century. But there could be a few more if our greenhouse gas emissions do not fall rapidly.