Climate crisis: Releasing bison, reindeer and horses into the Arctic would slow warming, say scientists

Releasing herds of animals into the Arctic could help tackle the climate crisis, researchers say.

A computerised simulation of conditions at the polar region found that with enough wildlife, 80 per cent of the world’s permafrost soils could be saved, preventing a vicious circle of environmental catastrophe.

Half of all permafrost areas – ground that is permanently frozen – are on course to thaw by the year 2100 at current rates of climate change, scientists say.

This is caused by rising emissions of greenhouse gases such as carbon dioxide, which are predicted to push up frozen land temperatures by 7F.

But experts in Germany calculated that if herds of horses, bison and reindeer repopulated the tundra, ground temperatures would rise by only 4F, protecting most of it from melting.

In exceptionally cold areas such as the Arctic, the air is even colder than the earth, and thick blankets of snow act as insulation on land, protecting it from the air and keeping it milder.

But grazing animals can keep the ground cool by dispersing snow and compressing the land, according to the study, published in the nature journal Scientific Reports.

When permafrost melts, it releases heat-trapping gases that have been buried for tens of thousands of years back into the atmosphere, so accelerating the climate crisis.

Last month scientists discovered the polar ice caps are melting six times faster than they were in the 1990s.

The new study was carried out by Professor Christian Beer and a team at the University of Hamburg, who replicated the impact of animals in the northern hemisphere over a year using data from the area.

“This type of natural manipulation in ecosystems that are especially relevant for the climate system has barely been researched to date, but holds tremendous potential,” Prof Beer said.

He told CBS News in the US that more research was needed but the results were promising.

“Today we have an average of five reindeers per square kilometre across the Arctic. With 15 reindeer per square kilometre we could already save 70 per cent permafrost according to our calculations.”

But he said he was unsure how realistic it was to expect the Arctic could be repopulated with enough animals.

“It may be utopian to image resettling wild animal herds in all the permafrost regions of the northern hemisphere, but the results indicate that using fewer animals would still produce a cooling effect,” he said.

The study was inspired by an experiment in the town of Chersky, Siberia, where more than 20 years ago scientist Sergey Zimov resettled grazing animals to Pleistocene Park, an area of Arctic tundra, CBS reported.

He found that 100 animals across 1sq km halved the average snow cover, dramatically reducing its insulating effect on the earth and intensifying permafrost.

“If theoretically we were able to maintain a high animal density like in Zimov’s Pleistocene Park, would that be good enough to save permafrost under the strongest warming scenario? Yes, it could work for 80 per cent of the region,” said Prof Beer.

He now wants to work with biologists to look at how animals would spread out across the landscape.

But Rick Thoman, a climate expert at the International Arctic Research Centre in Alaska, was sceptical.

He told CBS: “Unless the plan is to cover millions of square kilometres with horses, bison and reindeer, how could this possibly have any significant impact? I would not call it ‘utopian’ to destroy permafrost lands as we know them by having animals in the distribution and numbers required.”