Climate activists have long feared that the polar ice caps would melt away. In fact, the North Pole will be ice-free once in a few years, Hamburg scientists predict. Even radical climate protection can no longer change this.
Hamburg (dpa) - According to calculations by Hamburg scientists, the North Pole will be ice-free at least in some summers by 2050.
An analysis of 40 climate models showed that the ice in the Arctic Ocean would melt even if mankind achieved ambitious climate targets for carbon dioxide emissions.
"If we quickly and significantly reduce emissions worldwide and thus achieve the two-degree target, the Arctic ice will still melt off as much as possible in the summer before 2050," said the lead author of the study, Dirk Notz from the Center for Earth System Research and Sustainability the University of Hamburg. "That surprised us." The researchers published the study in the "Geophysical Research Letters".
Notz called the Arctic a major area of climate change. The sea ice is very sensitive and comparatively linear to global warming. Every ton of CO2 that is emitted causes three square meters of ice to melt.
If global warming were to be limited to two degrees, the North Pole would probably be largely ice-free in half of the summer to 2050, meaning that the pack ice would be less than a million square kilometers. If the climate only warmed by 1.5 degrees, an ice-free Arctic would remain an exception, according to Notz. "Even in the most optimistic scenario, the ice will disappear in some years," said the climate scientist. "It is probably too late."
The consequences for nature are problematic: the sea ice cover is a hunting ground and an indispensable habitat for polar bears and seals. At the same time, the ice sheet plays an important role in the climate system. The bright surface reflects sunlight into space and cools the Arctic.
In September 2019, according to the Bremer Alfred Wegener Institute, the second least extent of the Arctic ice was measured since 1979. Only 3.9 million square kilometers of the Arctic Ocean were frozen over. In September 2012, the smallest ice surface to date was observed at 3.4 million square kilometers. Arctic ice usually reaches its largest extent in March and its smallest extent in September.