The big thaw reaches Mongolia's pristine north

Global warming is not a uniform process. Mongolia, particularly at the high altitudes around Lake Hovsgol, has been warming more than twice as fast as the global average. Unique ecosystems are feeling the heat. Here at the transition between the steppe grassland and taiga, plants and animals are confronted with a changing environment-and the outlook is not good for the herders who are crowding up from the south.