Whether or not you believe that humans are causing the Earth to warm, it's indisputable that sea levels are rising, and experts agree that at the end of this century they will be between three and six feet higher than they are today, and it may already be too late to do anything to stop it. Some nations will find it harder to adapt than others, and some will be completely obliterated -- like the island nation of Kiribas, most of Micronesia (a collection of about 600 paradise-like atolls in the South Pacific), and a number of other places like the Maldives, whose president recently held a climate summit underwater, in scuba gear, as a darkly funny publicity stunt/plea for help.

A documentary at this year's Sundance festival, There Once Was An Island, tells the story of one of these seemingly doomed paradises, a culturally unique Polynesian community called Takuu where people have lived for thousands of years, but now rising seas are flooding houses, poisoning fields with saltwater, and threatening their ancient way of life. I've never seen this problem presented so dramatically before -- check out the trailer and see if you don't agree.