In Brief:
Observations from space show that the rate of sea level rise is increasing. Knowing where and how much rise is happening can help coastal planners prepare for future hazards.
The average global sea level rose by 0.11 inches (0.27 centimeters) from 2021 to 2022, according to a NASA analysis of satellite data. That’s the equivalent of adding water from a million Olympic-size swimming pools to the ocean every day for a year and is part of a multidecade trend of rising seas.
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.
This graphic shows rising sea levels (in blue) from data recorded by a series of five satellites starting in 1993. The solid red line shows the trajectory of rise from 1993 to 2022, illustrating that the rate of rise has more than doubled. By 2040, sea levels could be 3.66 inches (9.3 cm) higher than today. Credit: NASA/JPL-Caltech
“We have this clear view of recent sea level rise – and can better project how much and how quickly the oceans will continue to rise – because NASA and Centre National d’Études Spatiales (CNES) have gathered decades of ocean observations. By combining that data with measurements from the rest of the NASA fleet, we can also understand why the ocean is rising,” said Karen St. Germain, director of NASA’s Earth Science Division in Washington. “These fundamental climate observations help shape the operational services of many other federal and international agencies who are working with coastal communities to mitigate and respond to rising waters.”
The 2022 increase was less than the expected annual rate because of a mild La Niña. During years with an especially strong La Niña climate pattern, average global sea level can even temporarily drop because weather patterns shift in a way that leads to more rainfall over land inst …