In 2020, the Arctic is withdrawing faster than ever «kleinezeitung.at

For the first time, scientists have been able to measure and document the entire ice cycle from freezing to melting. An assessment of the next few years will only show whether Arctic sea ice can be saved year-round.

07.35 a.m., June 16, 2021

during the annual “Mosaic” – Expedition From Research ship “Polarstern” In the central Arctic, the ice is retreating faster than at any time since records began. Then-chief scientist Markus Rex of the Alfred Wegener Institute (AWI) said Tuesday in Berlin a provisional balance eight months after the end of the ice expansion in the summer of 2020 was only half its size decades ago. the campaign.

At the same time, the thickness of the ice was almost half of what it was 130 years ago. In the fall of 2020, the ice closed much later than ever. “The long ice-free time in the summer allowed the ocean to absorb and store large amounts of heat,” Rex said.

The total ice cycle was measured

“Polarstern” took off from Bremerhaven towards the North Pole in September 2019, and returned in October 2020. For ten months, the ship drifted across the Arctic Ocean, docked on a huge ice floe. Scientists were able to do everything for the first time The ice cycle from freezing to thawing Measure and document. They hope the data obtained will provide important insights into the Arctic Ocean – and global climate change.

More than 150 terabytes of data and tens of thousands of samples of ice, snow, water and air have been brought home, Rex said. “In about 300 ongoing individual science activities, we are in the process of compiling our knowledge of the Arctic climate system, piece by piece, from our measurements,” Rex said.

Can sea ice be preserved?

Only an assessment of the next few years will show whether Arctic sea ice can be saved year-round, Rex said. He warned that if the Arctic summer becomes ice-free, it could lead to “uncontrolled waterfalls”. These could continue to cause global warming. “The tipping point, which will lead to the disappearance of summer sea ice in the Arctic, is imminent,” Rex emphasized. “We may be the last generation to experience an ice-capped Arctic in summer,” said sea ice physicist Stephanie Arndt, one of 300 international researchers aboard the Polarstern.

Rex called for a significant and rapid reduction in emissions of greenhouse gases such as carbon dioxide in order to continue to achieve desired climate goals. In addition, there is an urgent need to work on new technologies by which carbon dioxide can be extracted from the atmosphere on a large scale. “We don’t have these technologies yet.”