Overview

• An international reconstruction spanning nearly 12,000 years concludes the 1900–2020 increase outpaced any period in at least four millennia.
• The study estimates an average rise of 1.51 millimeters per year from 1990 to 2020, with evidence of continued acceleration.
• A marked shift began in the 19th century, with average rates of about 0.1 millimeters per year early in the century rising to roughly 0.76 millimeters later.
• Recent rise is attributed mainly to ocean warming and added water from melting mountain glaciers and the Greenland and Antarctic ice sheets, with a strengthening acceleration signal reported in Greenland.
• Local risks vary due to land subsidence, including more than one meter of sinking in parts of Shanghai during the 20th century and sections of Jakarta now lying below sea level that require constant pumping.