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 US are studying the glacier's changes as part of the International Thwaites Glacier Collaboration.

The BBC's chief environment correspondent Justin Rowlatt visited the project.

During his trip, he also learnt how to make an igloo.