The world’s largest lakes are rapidly shrinking, endangering a critical source of freshwater for people around our planet. In a new study published in the journal Science, researchers analyzed satellite images and found that more than half of the world’s largest lakes have lost water.
The team analyzed satellite images of 1,972 of the largest lakes in the period from 1992 to 2020, examining long-term recorded water levels and recent water measurements. They found that 53% of these lakes lost water, and the total loss was 17 times the amount of water that could fill Lake Mead, the largest in the US.
A dry season can drastically reduce water levels, while the following year’s winter storms can replenish reserves. But the water loss cited in the study has been attributed to climate change and increased human activity, including the demand for greater water.
Changing climatic conditions are raising global temperatures, increasing evaporation in many parts of the world, and precipitation patterns are changing. In addition, sedimentation caused by the accumulation of sediments in lakes reduces their water storage capacity. This may also be linked in part to climate change, with more wildfires causing more sedimentary deposits to flow, researchers interviewed by CNN said.
As highlighted in the study, this loss of water occurs throughout the world, in both dry and humid regions.
Although lakes are a small portion of the planet’s surface, this is a major concern as they “store 87% of Earth’s liquid surface freshwater,” according to the study. These freshwater reserves are used for recreation, drinking water, hygiene, agriculture and travel. Researchers estimate that about 2 billion people, a quarter of the world’s population, live in the basin of a dried-up lake.
The researchers also created an interactive map based on their data.
“If human consumption is a large factor in lake water storage reduction, then we can adapt and explore new policies to reduce large-scale declines,” Ben Livneh, co-author of the study, said in a press release.
In the editorial brief for the study, the researchers stress that “water use practices need to be changed to better protect essential ecosystem services such as freshwater storage, food supply, waterfowl habitat, the cycling of pollutants and nutrients, and recreation.”
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