The top of our world is changing - warming twice as fast as the rest of the planet. And it is destroying communities. The island of Shishmaref (a town in Alaska) is on the frontline of climate change. As temperatures rise, less sea ice forms, exposing the coast.

As the climate changes, the animals and fish that people here used to live on are getting harder to find. Parts of the main road have been washed away, and now the airstrip that is the community’s lifeline to the outside world is threatened. The plan is to move the entire town onto the mainland. It will cost an estimated a hundred and eighty million dollars, but, says Dennis, they’ve got no choice. The climate’s changing so fast. And the storms are getting more violent, and the ice isn’t forming, and the water’s warming. Within the next five, ten years, this will all be covered easily. Just that one or two degrees makes a big difference.

It isn’t easy to let go of the place where you’ve spent your entire life. But if greenhouse gas emissions aren’t cut rapidly, it is something many millions more people are likely to have to face.