“We always assumed that people’s increased reliance on groundwater for irrigation and consumption was resulting in a net transfer of water from the land to the ocean,” said lead author J.T. Reager of JPL, who began work on the study as a graduate student at UC Irvine. “What we didn’t realize until now is that over the past decade, changes in the global water cycle more than offset the losses that occurred from groundwater pumping, causing the land to act like a sponge — at least temporarily. These new data are vital for understanding decadal variations in sea level change. The information will be a critical complement to future long-term projections of sea level rise, which depend on melting ice and warming oceans.”

The 2002 launch of NASA’s Gravity Recovery and Climate Experiment (GRACE) twin satellites provided the first tool capable of quantifying land liquid water storage trends. By measuring the distance between the two GRACE satellites to within the width of a strand of human hair as they orbit Earth, researchers can detect changes in Earth’s gravitational pull that result from regional changes in the amount of water across Earth’s surface. With careful analysis of these data, JPL scientists were able to measure the change in liquid water storage on the continents, as well as the changes in ice sheets and glaciers.
“These results will lead to a refinement of global sea level budgets, such as those presented in the Intergovernmental Panel on Climate Change (IPCC) reports, which acknowledge the importance of climate-driven changes in hydrology, but have been unable to include any reliable estimate of their contribution to sea level changes,” said JPL senior water scientist Jay Famiglietti, senior author of the paper and a professor at the University of California, Irvine.
Famiglietti also noted the study is the first to observe global patterns of changes in land water storage, with wet regions getting more wet and dry areas getting drier.
“These patterns are consistent with earlier observations of changing precipitation over both land and oceans, and with IPCC projections of changing precipitation under a warming climate,” he said. “But we’ll need a much longer data record to fully understand the underlying cause of the patterns and whether they will persist.”
NASA uses the vantage point of space to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth’s interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.
Republished from NASA.gov in accordance with the NASA media usage policy and public domain rights. Original article published on the NASA website.
Next, Check Out:
- Two Degrees to Disaster – New Climate Study is a Wake Up Call
- He Predicted Climate Change but Where is he Now?
- Climate Change Affected the Evolution of Dogs
- A Fascinating New Theory about What Happened to the Neanderthals
- [Video] New genetically engineered American chestnut will help restore the decimated, iconic tree