What happens when permafrost melts in the summer?

As the name suggests the permafrost is permanently frozen, summer and winter. The surface may have some liquid water, but the deeper layers are cold enough not to thaw.

This situation is changing as global climate change progresses. The permafrost will disappear leaving vast tracts of boggy land that are not capable of walking on (bad news for the communities and migrating herds of caribou). In addition the melting permafrost will release vast quantities of methane gas which will make climate change even more severe.