Threatening the Inupiat village of Selawik, Alaska, are sinkholes that have formed beside the river that provides the community its drinking water, as well as an important food source.

In the Eureka Sound Lowlands on Ellesmere and Axel Heiberg islands, the permafrost is more than half a kilometre deep, and the average air temperature is –19.7 C. But higher summer temperatures have caused the earth to collapse.