Fire and ice

Making fire from ice may sound like the impossible. But that's exactly what scientists have been able to do in the wilderness of the Arctic as a sleeping giant begins to stir. Ground that's been frozen for thousands of years is rapidly thawing out, releasing dangerous gases on a colossal scale. The result is not only wreaking chaos on local communities but has the potential to rapidly accelerate global warming. Just before the planes stopped flying, Sarah Abo travelled to spectacular Alaska to investigate this worrying new environmental threat that has profound implications for us all.

Reporter: Sarah Abo

Producer: Nick Greenaway