Over the last two decades, the planet has faced significant losses in freshwater resources due to climate change, overuse, and drought.
Research indicates that arid regions are growing at approximately twice the area of California each year, leading to a disturbing trend where dry areas are becoming drier at a faster pace than wet areas are becoming wetter. This development has altered historical water distribution patterns.
Experts caution that this “megadry” phenomenon on a continental scale could have severe implications for water security, agriculture, sea levels, and global stability. In fact, researchers found that about 75% of the global population resides in 101 countries that have experienced a loss of freshwater over the past 22 years.
Jay Famiglietti, a professor focusing on sustainability at Arizona State University, expressed that the findings reveal shocking impacts of climate change on water resources.
“The continent is becoming drier, with freshwater availability declining and sea levels rising,” Famiglietti added.
To evaluate changes in terrestrial water reserves, researchers combined over two decades of satellite data from NASA’s Gravity Recovery and Climate Experiment missions.
They examined various types of water reserves, such as soil moisture, snow, and all surface water stored on land.
Ultimately, the researchers noted significant changes in these water reserves compared to previous worldwide assessments.
The decline has been largely attributed to substantial water losses observed in high-latitude regions like Russia and Canada, severe reductions in Central America and Europe, as well as groundwater depletion.
Interestingly, the researchers pinpointed a crucial period between 2014 and 2015, often associated with the “Mega El Niño.” During this time, meteorologists noted shifts in climate patterns in North America, characterized by increased dryness and warmth in the Northern states while the south faced more flooding.
Close to this tipping point, climate extremes started to intensify, and studies indicate that the use of groundwater, alongside increasing continental aridity, has outpaced the melting of glaciers and ice sheets.
Analyzing 22 years of data, scientists discovered that certain areas experiencing water loss were actually interconnected, concluding they represent four major mega-dry regions.
The first is located in the southwest U.S., Mexico, and Central America, encompassing many key agricultural zones. The second region affects Alaska and northern Canada, where agricultural areas are experiencing dryness due to snow and melting permafrost.
Northern Russia forms the third key area, marked by significant melting snow and permafrost in high-latitude regions.
The fourth area includes the Middle East, North Africa, and parts of Eurasia, which contain numerous major desert cities, critical food production hubs, and shrinking bodies of water.
Lead author Hrishikesh Chandanpurkar, a research scientist in Arizona, remarked on the alarming rate at which non-renewable water resources are vanishing.
“Glaciers and deep groundwater serve as our ancient trust funds,” he explained. “Instead of using them sparingly during times of drought, we often take them for granted.”
Chandanpurkar also cautioned that humans are failing to replenish groundwater resources during rainy seasons, leading to an increased risk of “immediate freshwater bankruptcy.”
Describing their findings as a “call to awaken the planet,” the researchers emphasized the importance of continued research to aid policymakers in addressing these severe water challenges.
They also highlighted the need for community-level initiatives to address the issue of excessive groundwater extraction.
Famiglietti warned that relentless use of the remaining groundwater could jeopardize food and water security for billions worldwide.
“This is a critical moment,” he stated. “Immediate action is needed to ensure global water security.”
