in northern siberia, there are signs the frozen tundra is starting to thaw for the first time in thousands of years. this could speed up global warming by releasing even more greenhouse gases. for one family -- one family of russian scientists is trying to fight climate change in the arctic. that is the ice age that is their inspiration. >> it is sunrise in the siberian tundra. light changes every few minutes. in december when the polar night begins, the sun will not rise at all. scientists -- the scientist grew up here, the coldest inhabited region in the world. he wants to show us how much and how quickly his home is changing. there are small signs everywhere. the ruts in the road and more snow than is usual for this time of year. >> the world's oceans have become warmer, so more water evaporates. and that is why there is more precipitation here. all of this snow is warmer than the arctic permafrost. that is causing it to thaw. >> permafrost is permanently frozen subsoil. the effects of permafrost thaw are clearly visible in the lakes here. under here, there are billions of tons of froze