NASA 30-Year Satellite Record Finds Rapid Sea Level Rise, Increasing by 9.1 cm

NASA's Sea Level Change science team has reported a rapid increase in the global sea level, rising by 9.1 cm in the past 30 years.

The satellite data analysis shows that the average global sea level has risen by 0.11 inches (0.27 cm) from 2021 to 2022, equivalent to adding water from a million Olympic-size swimming pools to the ocean every day for a year.

Multi-decade Trend of Rising Seas

This increase is part of a multi-decade trend of rising seas. The annual rate of rise has also increased from 0.08 inches (0.20 cm) per year in 1993 to 0.17 inches (0.44 cm) per year in 2022.

By 2050, the estimated rate of sea level rise will be 0.26 inches (0.66 cm) per year, according to long-term satellite data.

NASA notes that these measurements of sea surface height that began 30 years ago with TOPEX/Poseidon continued through four subsequent missions led by NASA and partners, including the French space agency CNES, ESA (European Space Agency), and the US National Oceanic and Atmospheric Administration (NOAA).

These measurements will be continued through 2030 by the most recent mission in the series, Sentinel-6/Jason-CS (Continuity of Service), which comprises two satellites. Sentinel-6 Michael Freilich, the first of these two spacecraft, was put into orbit in 2020, and Sentinel-7 is scheduled to do the same in 2025.

Human-caused Climate Change

The rapid rise in sea level is caused by human-caused climate change driven by the excess amounts of greenhouse gases like carbon dioxide that society pumps into the atmosphere, as per NASA.

As heat causes seawater to expand, climate change is melting the ice sheets and glaciers on Earth, adding more fresh water to the ocean. Both of these factors contribute to rising seas, outweighing many other natural forces that affect sea surface height.

"The 30-year satellite record allows us to see through the shorter-term shifts that happen naturally in the ocean and helps us identify the trends that tell us where sea level is headed," JPL's Ben Hamlington, a sea level researcher who leads NASA's Sea Level Change science team, said in a statement.

Researchers now have a better picture of how the ocean is currently behaving on a global scale thanks to scientific and technological advancements made by NASA and other satellite organizations.

Particularly, radar altimeters have contributed to the global sea level readings becoming ever more accurate.

To measure the height of the sea level, they monitor the time it takes for a microwave signal to travel from a satellite to Earth and back while also recording the strength of the return signal.