SNOWBALL EARTH - HDTV 2008 Eng.sub

Imagine a world frozen solid. Imagine that vast sheets of ice, hundreds of metres thick, encased the entire planet - a giant snowball floating through space. This is not some exotic new world deep in space - it may have been our world, the Earth. In this episode, Naked Science explores what may have been the most extreme period of Earth's climatic history. Some top-ranking scientists believe that in the past the Earth completely froze over for millions of years... then warmed up rapidly approximately 600 million years ago. Struggling against skepticism and disbelief for years, these experts have gathered a growing body of evidence supporting the claim, and others in the scientific community are slowly coming around to the incredible idea - not just of the dramatic freeze, but of an equally extraordinary thaw.