Excerpt from bbc.com

From erecting seawalls to selling citizenship, vulnerable small islands are taking sometimes drastic measures to protect themselves from rising seas, storms and economic devastation.

For decades now, scientists have been warning that without action to combat emissions, some low-lying islands will literally disappear beneath the waves. Many others will become uninhabitable as extreme weather increasingly batters their coastlines.

As the world edges closer to a long-term average of 1.5C warming, these warnings are becoming a seriously imminent prospect for some island nations. Five islets in the Solomon Islands, a nation of hundreds of islands in the South Pacific, have already been completely lost to sea level rise. And many small island developing states are seeing substantial annual economic losses due to coastal floods. By 2050, coastal flooding is set to triple across these nations, increasing annual economic damages by nine to 11 times.

Small islands have become a strong voice in international forums, pushing for more ambitious climate policies to curb global temperature rise, and were key to the 2015 Paris Agreement to pursue efforts to limit temperature rise to 1.5C. But they are increasingly facing some stark choices about how to physically stay above the waves, as well as in their diplomatic pushes for money to weather an increasingly uncertain climate.