The study lays out Kiribati’s future in apocalyptic detail. Causeways would be washed away, crippling the economy; degraded coral reefs, damaged by warming water, would allow stronger waves to slam the coast, increasing erosion, and would disrupt the food supply, which depends heavily on fish supported by the reefs. Higher temperatures and rainfall changes would increase the prevalence of diseases like dengue fever and ciguatera poisoning.

Even before that, scientists and development experts say, rising sea levels are likely to worsen erosion, create groundwater shortages and increase the intrusion of salt water into freshwater supplies.

In response, Kiribati (pronounced KEE-ree-bas in the local language) has essentially been drawing up plans for its demise. The government has promoted “migration with dignity,” urging residents to consider moving abroad with employable skills. It bought nearly 6,000 acres in Fiji, an island nation more than 1,000 miles away, as a potential refuge. Fiji’s higher elevation and more stable shoreline make it less vulnerable.

Anote Tong, a former president who pushed through the Fiji purchase, said it was also intended as a cry for attention from the world. “The issue of climate change is real, serious, and we’d like to do something about it if they’re going to take their time about it,” he said in a recent interview.