evidence: Since satellites began observing sea surface height in 1993 with the U.S.-French TOPEX/Poseidon mission, the average global sea level has increased by 3.6 inches (9.1 centimeters), according to NASA’s Sea Level Change science team. The annual rate of rise – or how quickly sea level rise is happening – that researchers expect to see has also increased from 0.08 inches (0.20 centimeters) per year in 1993 to 0.17 inches (0.44 centimeters) per year in 2022. Based on the long-term satellite measurements, the projected rate of sea level rise will hit 0.26 inches (0.66 centimeters) per year by 2050. [...] Despite natural influences like La Niña, sea levels continue to rise because of human-caused climate change driven by the excess amounts of greenhouse gases like carbon dioxide that society pumps into the atmosphere. Climate change is melting Earth’s ice sheets and glaciers, adding more fresh water to the ocean, while warming causes the expansion of seawater. Both of these effects contribute to rising seas, overriding many natural effects on sea surface height. [...] When altimetry data from all ocean basins is combined with more than a century of observations from coastal surface-based sources, together they dramatically expand and improve our understanding of how sea surface height is changing on a global scale. And when those measurements of sea level are combined with other NASA data sets on ice mass, land motion, and other Earth changes, scientists can decipher why and how seas are rising.