Sea Levels Have Gone Up 3 Inches Since 1992, but NASA Predicts Much Worse for the Future

NASA measures sea level rise from space, and the outlook isn’t good.

In less than 25 years, the world’s global sea level has gone up an average of three inches (eighty millimeters), and is rising faster than it was 50 years ago, according to a group of NASA scientists. Yesterday, NASA’s Sea Level Change Team shared some of their findings, which includes data on sea levels measured from space using satellites.

Sea level rise isn’t evenly distributed around the world. In some areas, the sea has risen as much as 9 inches (23 centimeters), while in other places the sea level has dropped. For example, on the West Coast of the United States sea levels have actually been lower over the past 20 years, due to temporary ocean cycles. But when these cycles end, the impact of climate change is expected to be seen.

NASA predicts that oceans will continue to rise at a considerable rate, about 0.1 inch (3.21 millimeters) per year on average. In 2013, the UN Intergovernmental Panel on Climate Change (IPCC) predicted sea level rise would be between one and four feet (0.3 to 1.2 meters) by the year 2100. NASA’s data suggest the higher end of the range.

“It’s pretty certain we are locked into at least three feet of sea level rise, and probably more,” said Steve Nerem of the University of Colorado during the live streamed event.

Sea level rise is driven by a number of factors related to global warming. As ocean temperatures rise, water expands and creeps up on land. Melting ice sheets, such as in Greenland and Antarctic, also add more water to Earth’s oceans, as well as water from melting mountain glaciers.