 According to the United States Census Bureau, the town has a total area of , all of it land.The island is at risk of disappearing due to erosion and rising sea levels caused by climate change; since 1850, the island's landmass has been reduced by 67%.Under a mid-range sea level rise scenario, much of the remaining landmass is expected to be lost in the next 50 years and the town will likely need to be abandoned.