The Arctic permafrost really should stay frozen. In many places it’s been frozen for tens of thousands of years, locking away greenhouse gasses and ancient diseases.

Unfortunately, our planet’s changing climate is denting permafrosts around the world. And now NASA-funded research has confirmed that the expected gradual thawing of the Arctic permafrost is being dramatically sped up by a natural phenomenon known as thermokarst lakes.

These lakes form when a lot of ice in the deep soil melts. Water takes up less space than ice, so this leaves room for water to collect from other sources as well, including rain and snow.