New satellite data reveals a troubling truth: since 2002, Earth’s continents are drying rapidly. This is not a temporary drought but a global reconfiguration of freshwater balance. Climate change, groundwater misuse, and long droughts have driven this shift.
A study led by Arizona State University highlights four massive “mega-drying” zones in the Northern Hemisphere. The researchers analyzed over 22 years of data from the GRACE and GRACE-FO satellites.
They found that these drying regions are expanding by about 831,600 km² [321,000 sq mi] each year. That is roughly twice California’s size.
Groundwater loss and drying continents
The study found a major imbalance. Dry zones are drying faster than wet zones are gaining water. Since 2014, dry extremes have surged, rising one million square miles per year in non-glaciated areas. This points to a major climate-driven tipping point linked to mega El Niño events.
About 75% of humanity, over 6 billion people, live in 101 countries that have lost freshwater since 2002. This overlap of population growth and freshwater decline threatens global stability.
Groundwater accounts for 68% of the total land-based water loss. In drying regions, it now contributes more to sea level rise than Greenland’s glaciers. Surface water (18%), soil moisture (9%), and snow water (5%) follow behind.
“These findings send perhaps the most alarming message yet about the impact of climate change on our water resources,” said Jay Famiglietti. “Continents are drying, freshwater availability is shrinking, and sea level rise is accelerating.”
Four huge regions are drying
The study outlines four interconnected drying belts that now form vast, expanding zones of water loss across the Northern Hemisphere. In Northern Canada and Alaska, terrestrial water storage is declining at a rate of −0.34 inches per year, excluding glaciers.
Northern Russia follows with a drop of −0.16 inches per year, driven by permafrost thaw and ongoing droughts. Southwestern North America and Central America show a combined decline of −0.30 inches per year, affecting major urban centers like Las Vegas, Los Angeles, and Mexico City.
The most severely impacted is the MENA and Pan Eurasia region, where the Ganges-Brahmaputra Basin is losing −0.43 inches per year, and the Caspian and Aral Seas show an even steeper decline of −1.18 inches per year. What were once isolated hotspots have now merged into broad, continental-scale drying belts.
Dry continents are raising sea levels
Before 2014, most extreme drying occurred in the Southern Hemisphere. After 2014, the trend reversed. Most dry extremes now occur in the North and last longer. This flip aligns with the strongest El Niño event on record.
While wet regions have shrunk, the tropics remain the exception. Wetting continues near the equator but less than expected by IPCC climate models.
The land now contributes 44% of mass-driven sea level rise. This is more than Greenland or Antarctica. The annual contribution from drying non-glaciated land regions is 0.04 inches in sea level equivalent. Groundwater alone contributes 68% of that.
These changes are long-lasting. Over 62% of drying areas show trends persistent across 22 years. In contrast, many wetting trends are less robust and driven by temporary wet events.
Water lost faster than it can be replaced
Regions already facing water stress, like the Indus Basin, North China Plain, and Central Valley, now experience 10% or more annual water loss compared to their renewable supply. Half of the world’s major aquifers are depleting fast.
Groundwater systems are like ancient trust funds. Once drained, they cannot be restored in human timeframes.
“It is striking how much non-renewable water we are losing,” said Hrishikesh A. Chandanpurkar, lead author of the study and a research scientist at ASU.
“Glaciers and deep groundwater are sort of ancient trust funds. Instead of using them only in times of need such as a prolonged drought, we are taking them for granted. Also, we are not trying to replenish the groundwater systems during wet years and thus edging towards an imminent freshwater bankruptcy.”
A global wake-up call
Famiglietti warns that continuing this path will undermine food and water security for billions. But there is a path forward.
“This research matters. It clearly shows that we urgently need new policies and groundwater management strategies on a global scale,” noted Famiglietti.
Urgent actions must focus on reducing groundwater overuse, boosting recharge, and protecting aquifers. Coordinated international efforts could slow drying and reduce sea level rise.
The findings from this study will inform an upcoming World Bank report on the water crisis. It will offer practical solutions to governments facing water scarcity.
Until then, the message is clear. Earth’s continents are drying. Water is vanishing faster than nature can replace it. The time to act is now.
The study is published in the journal Science Advances.
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