New research based on 22 years of satellite data has revealed that vast regions of the world are losing freshwater at alarming rates, pushing nearly six billion people—three-quarters of the global population in 101 countries—into water scarcity.
The study, published in Science Advances, shows the emergence of “mega-drought zones” stretching from North America to Asia, the Middle East, and across Africa into Europe. Among the hardest-hit regions are Canada, Russia, southwestern North America, Central America, northern China, Southeast Asia, and a massive belt of drought extending from North Africa to France.
Since 2002, satellites have tracked changes in Earth’s gravity field to monitor shifts in water reserves. The data show that humanity is not only facing drier conditions but also failing to “live within its water limits,” according to study co-author Hrishikesh Chandanpurkar of Arizona State University. “The truth is that water is undervalued, and long-term reserves are being exploited for short-term gains,” he said.
The study estimates that groundwater depletion accounts for 68 percent of water loss in dry regions, now surpassing the melting of mountain glaciers as a driver of sea-level rise. Dry areas are losing 368 billion metric tons of water each year—more than twice the volume of Lake Tahoe or ten times that of Lake Mead, the largest U.S. reservoir.
Expanding drought zones
Scientists identified sprawling drought corridors, including one from the western United States through Mexico into Central America, and another stretching from Morocco across the Middle East into northern China. The drivers, the study notes, are twofold: rising global temperatures fueled by fossil fuel use, and overpumping of groundwater that took thousands of years to accumulate.
“This may be the most alarming message yet about how climate change is transforming our water resources,” said Jay Famiglietti, a water scientist at Arizona State University and co-author of the study. “The planet’s water cycle has shifted rapidly over the past decade, triggering a wave of fast-moving droughts.”
Each year, the world’s drought zones expand by an area nearly twice the size of California. Canada and Russia are losing the greatest volumes of freshwater due to melting ice and permafrost, while the U.S., Iran, and India face severe losses from rising temperatures and chronic overuse of aquifers.
Groundwater depletion and sea-level rise
High-powered pumps used by farms and cities extract such large amounts of water that much of it evaporates and falls as rain over the oceans, contributing significantly to rising sea levels. The study found that groundwater loss now adds more to sea-level rise than the melting of glaciers in Greenland, Antarctica, or mountain ranges worldwide.
Between 2002 and 2024, depleted lands and aquifers added 22.2 millimeters of water to the world’s oceans. Once groundwater tables fall, wells dry out, land can subside, and the damage is often irreversible.
The implications are stark: farmers may struggle to grow enough food, economic growth could be undermined, populations in dry regions may be forced to migrate, and competition over water resources is already fueling conflicts. “As aquifers are drained, water bankruptcy is inevitable,” Famiglietti warned.
Chandanpurkar stressed the urgency of the findings: “It is deeply concerning. Water affects everything in life, and the irreversible decline we are seeing will ripple across societies and generations.”
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