Global warming may have already passed its irreversible tipping point, scientists leading the biggest-ever expedition to the Arctic have warned.
Presenting the first findings of the world’s largest mission to the North Pole, an expedition involving 300 scientists from 20 countries, Markus Rex said on Tuesday that the researchers had found that Arctic ice is retreating faster than ever before.
“The disappearance of summer sea ice in the Arctic is one of the first landmines in this minefield, one of the tipping points that we set off first when we push warming too far,” he said during the presentation in Germany’s capital, Berlin.
“And one can essentially ask if we haven’t already stepped on this mine and already set off the beginning of the explosion.”
The team of scientists returned to Germany in October after 389 days drifting through the Arctic, bringing home devastating proof of a dying Arctic Ocean and warnings of ice-free summers in just decades. It also brought back 150 terabytes of data and more than 1,000 ice samples.
The data collected during the expedition included readings on the atmosphere, ocean, sea ice and ecosystems.
The abundance of information was feed into the development of models to help predict what heatwaves, heavy rains or storms could look like in 20, 50 or 100 years.
Rex said scientists found that the Arctic Ocean ice had retreated “faster in the spring of 2020 than since the beginning of records” and that “the spread of the sea ice in the summer was only half as large as decades ago.”
The ice was only half as thick and temperatures measured 10 degrees higher than during the Fram expedition undertaken by explorers and scientists Fridtjof Nansen and Hjalmar Johansen in the 1890s.
Because of the smaller sea ice surface, the ocean was able to absorb more heat in the summer, in turn meaning that ice sheet formation in the autumn was slower than usual.
Stefanie Arndt, who specialises in sea ice physics, said it was “painful to know that we are possibly the last generation who can experience an Arctic which still has a sea ice cover in the summer”.
“This sea ice cover is gradually shrinking and it is an important living space for polar bears,” said Arndt, recalling observations of seals and other animals in the polar habitat.