Beware the thawing permafrost.

In the coldest parts of the world, there’s a layer of soil that stays frozen all year. This layer is called permafrost; it exists mainly around the Arctic, and acts kind of like a giant freezer. As plants and animals in those regions die, some of them become preserved in this permafrost.

But as human activity releases greenhouse gases into the atmosphere, the permafrost is starting to thaw and shrink. That’s having some dramatic consequences — and not just for people who live in the Arctic.

You can read more about the thawing Arctic permafrost here: https://www.vox.com/2017/9/6/16062174/permafrost-melting

VOX