How scientists can see Earth’s permafrost thawing from space

To start, the US has significant military infrastructure in Alaska: It’s home to six military bases and 49 National Guard posts, as well as 21 missile-detecting radar sites. Most are vulnerable to thaw now or in the near future, given that 85% of the state is on permafrost. 

Beyond American borders, the broader north is in a state of tension. Russia’s relations with Northern Europe are icy. Its invasion of Ukraine has left those countries fearing that they too could be invaded, prompting Sweden…