Tribespeople at risk as Siberia continues to defrost

A large chunk of northern Russia is tundra where the ground is hardened by the arctic conditions into permafrost. Yet even in these harsh climes humans manage to thrive - like the Nenet people, whose nomadic reindeer-herding way of life takes them across north-west Siberia.

But as climate change takes hold, the permafrost is melting, releasing large quantities of carbon dioxide and methane. It's causing problems for the Nenet, altering the availability of their reindeers' food as well as prompting other changes in the local eco-system.

Photographer Steve Morgan recently paid them a visit on behalf of Greenpeace, and brought back an astonishing collection of images illustrating both the Nenet's way of life and the abrupt climatic changes they are struggling to cope with. The Guardian have published an impressive slideshow of his photos, and here are a few more to add to the collection.