Journey to the Doomsday Glacier

Glaciologists have described Thwaites Glacier as the "most important" glacier in the world, the "riskiest" glacier, even the "doomsday" glacier. Scientists from the UK and the US are studying the glacier's changes as part of the International Thwaites Glacier Collaboration. The team wants to discover why it is melting so quickly - science with implications for us all. But during the trip the weather closes in, playing havoc with their plans. Will the expedition succeed in unlocking the secrets of the glacier? Antarctica is one of the most remote and inhospitable places on earth. Just how hard is it to live and work in such an extreme environment at the end of the world? The BBC's chief environment correspondent Justin Rowlatt visited the project.