It’s one of the most worrisome effects of global warming in the Arctic: The permafrost is beginning to thaw, and it’s releasing greenhouse gases that could actually accelerate climate change and threaten future generations.

If this continues unchecked, “You will die,” says Russian ecologist Sergey Zimov, who runs a research outpost called the Northeast Science Station. “Maybe not you, but there is no chance for your grandchildren.”

There are more greenhouse gases like methane and carbon dioxide trapped in the deep layers of permafrost — ground that’s frozen year-round, covering nearly a quarter of the North Hemisphere — than there are in all human fossil fuel emissions released since the beginning of the industrial age. As the permafrost thaws, trapped carbon is starting to escape into the atmosphere, creating a warming feedback loop that will make climate change even worse, and cause the permafrost to thaw even faster.

Among the innovative climate pioneers working to save the planet, Zimov is out to prove that recreating the ancient Arctic ecosystem could be a viable way to halt the threat of permafrost.