The tipping point for irreversible global warming may have already been triggered, Markus Rex, the scientist who led the biggest-ever expedition to the Arctic, warned Tuesday.
“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,” Rex said.
“And one can essentially ask if we haven’t already stepped on this mine and already set off the beginning of the explosion,” he added.
Rex led the world’s biggest mission to the North Pole, an expedition involving 300 scientists from 20 countries. The expedition returned to Germany in October after 389 days of drifting through the Arctic.
When they returned, they warned that polar ice was melting and that the Arctic could be ice-free within a few decades if humanity does not change course.
The 140-million-euro ($165-million) expedition brought back 150 terabytes of data and more than 1,000 ice samples.
Presenting their first findings, Rex said scientists found that the Arctic sea 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.
Without ice, polar bears can’t survive
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,” Arndt said. Polar bears depend on ice to hunt and store energy for summer and autumn when there’s less food.
With ice melting so fast in the Arctic, the animals are having a hard time finding food. In July last year, scientists said that climate change is starving polar bears into extinction. If humans don’t change, the animals will disappear by 2100.