Over the past 30 years, global average sea level has risen a total of 3.6 inches (9.1 centimeters), as indicated in this graphic, which is based on sea level measurements (in blue) from five successive satellites starting with the U.S.-French TOPEX/Poseidon mission in 1993. The solid red line shows the trajectory of sea level rise from 1993 to 2022, while the dotted red line shows the increase sea level into the future. Researchers can take the solid red line and calculate the rate of sea level rise, which was 0.08 inches (0.20 centimeters) per year in 1993 and doubled to 0.17 inches (0.44 centimeters) per year by 2022. The dotted red line shows that by 2040, sea levels may rise by an additional 3.66 inches (9.3 cm) above 2022 levels. The trajectory shown in the solid and dotted red line is based on work by the NASA Sea Level Change Team and the Ocean Surface Topography Science Team.