As the settlement of Kwigillingok thaws, infrastructure is crumbling (Credit: Alamy)

The consequences, if this thawing continues, will be profound, for Alaska – and for the world. Nearly 90% of the state is covered in permafrost, which means entire villages will need to be relocated, as the foundations of buildings and roads crumble. And if this frozen cache releases the millennia of accumulated carbon it has locked within, it could accelerate the warming of our planet – far beyond our ability to control it.