Pacific Island Nations and Rising Sea Levels

Global mean sea level, measured by satellite altimetry since 1993, has risen at an average rate of roughly 3.3 to 4 millimeters per year, with the Intergovernmental Panel on Climate Change's Sixth Assessment Report (2021) projecting further increases of several tenths of a meter to over a meter by 2100 depending on emissions pathways and ice-sheet dynamics. This rise is not distributed evenly: trade-wind-driven ocean circulation has concentrated disproportionately high rates of sea-level rise in the western tropical Pacific over recent decades, placing the region's low-lying atoll nations among the most exposed places on Earth. Tuvalu, a nation of nine coral atolls and reef islands with a highest natural elevation of only about 4.6 meters and a population concentrated on the narrow islet of Funafuti, has become an emblematic case, alongside Kiribati, the Marshall Islands, and Tokelau, all of which sit almost entirely at or near sea level.