Lakes Are Drying Up All Over the World

Over half the world's lakes are drying up, scientists have found, and it's mostly our fault.

According to a new paper published on Thursday in the journal Science, 53 percent of lakes worldwide have shrunk between 1992 and 2020.

This level of water loss is equivalent to 17 Lake Meads, the authors say, which is the largest reservoir by volume in the U.S.

"We would say this is a global pattern of drying," lead author Fangfang Yao, a CIRES (Cooperative Institute for Research in Environmental Sciences) visiting fellow at the University of Colorado Boulder, and climate fellow at the University of Virginia, told Newsweek. "The drying is evident in both arid and humid regions, such as western Central Asia, the Middle East, western India, eastern China, northern and eastern Europe, Oceania, the conterminous United States, northern Canada, southern Africa, and most of South America."

To get to this conclusion, Yao and his fellow authors analyzed 250,000 lake-area snapshots of 1,972 of Earth's biggest lakes—comprising 95 percent of lake water on the planet—captured by satellites over the past three decades. They also used long-term water level records to reduce uncertainty in their data.

"We combined water areas mapped from satellite imagery and water levels estimated from satellite altimeters to construct near-monthly lake volume time series from 1992 to 2020. Based on the time series data, we estimated the trends for Earth's large water bodies. We de-seasonalized the time series data and thus the seasonal fluctuations were removed before calculating the trends," Yao said.

Their findings can be seen in an interactive map.

Many lakes across the U.S. have also suffered from water losses in recent years, as a result of the ongoing megadrought plaguing the region. Lake Mead reached record lows in the summer of 2022, potentially heading towards dead pool levels later this year, and the Great Salt Lake also hit a record-low water level a few months ago, having lost 73 percent of its water.

Unfortunately, as with so many rapid changes to the climate in recent years, these worldwide lake water losses are driven by human action.

"More than half of the net water loss in natural lakes is attributable to direct human impacts (i.e. human consumption) and indirect human impacts (e.g. climate warming)," Yao said. "We are not confident to project the trends into the future, which requires additional efforts. For about 100 drying (large) lakes that were largely driven by warming, it is likely that the drying trends will be continued under a warmer climate."

This huge drop in lake water across the world in only 30 years is bad news: freshwater lakes are responsible for storing 87 percent of the planet's fresh water, and provide millions of people with essential drinking water and agricultural water.

"We did not quantify the impacts of drying lakes. Instead, we estimated the number of populations residing in a basin with a drying lake. We found roughly one-quarter of the world's population residing in these basins," Yao explained.

"Widespread LWS [lake water surface] decline, particularly accompanied by rising lake temperatures, could reduce the amount of absorbed carbon dioxide and increase carbon emissions to the atmosphere given that lakes are hotspots of carbon cycling. Drying lakes can cause freshwater loss, environmental degradation (e.g., receding shorelines, increasing salinity, deteriorating water quality, associated with level declines). A drying hydroelectric reservoir may lead to a reduction in hydropower energy generation. There may be other impacts on navigation, recreation...," Yao said.

Additionally, the drying of lakes could be harder to manage and mitigate, due to the bureaucracy surrounding refilling lakes.

"Lakes are often used for water supply as stand-alone resource," Balaji Rajagopalan, co-author of the paper and professor of hydrology and water resources at the University of Colorado, Boulder, told Newsweek. "This leaves the management to local entities. As a result, they are not integrated with other water resources managed by public entities. This leads to over-exploitation and sub-optimal management."

"It is hard to resurrect a drying or dried lake. Hence, pre-empting this with smart management is essential. This is especially critical in a warmer world," Rajagopalan said.

Not everything the authors found was bad news, however: they also discovered that 24 percent of lakes actually increased in their water storage, mostly in underpopulated areas in the inner Tibetan Plateau in Nepal and the U.S.'s Northern Great Plains, as well as in areas with newer reservoirs such as the Yangtze, Mekong, and Nile river basins.

With the current trajectory of climate change, which is forecast to lead to a global average temperature increase of 2.7 degrees Celsius—around 5 degrees Fahrenheit—by the year 2100, this lake drying issue is only likely to get worse.

"Looking ahead, while it's likely that changes in climate will continue, water management and the human consumption part is something that we do have control over," Ben Livneh, an associate professor of hydrology at the University of Colorado Boulder and co-author of the paper, told Newsweek.

"Solutions must involve a combination of awareness—like what we have raised in this study, better monitoring, as well as actionable management that prioritizes healthy lake levels. You can see good examples of management, like on the Colorado basin where specific water elevations trigger action, whereas bad examples are like the Aral Sea where unsustainable diversion led to a catastrophic loss of one of the world's largest lakes," Livneh said.

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