Climate change is wreaking havoc across the globe, upending weather patterns and the Earth’s hydrological cycle with often dramatic effects on some of the largest water bodies. 2024 was the hottest year on record, and there are concerns that these pressures on the Earth’s water system are likely to increase as the climate crisis continues.
One classic example is the Aral Sea. Once one of the largest lakes in the world, it has shrunk to only a fraction of its size.
“In 2016, this lake was less than 10 percent of its previous extent in 1960,” says Fangfang Yao, a climate scientist with the Cooperative Institute for Research in Environmental Sciences at University of Colorado Boulder. Climate change is one factor that has driven that loss, along with diversion for irrigation and agriculture.
Bodies of Water Across the Globe
The Aral Sea is far from alone. The Caspian Sea, the world’s largest inland water body, is shrinking as temperatures rise and rainfall drops. Studies suggest that by the year 2100, water levels might plummet by as much as 30 meters.
Lake Chad is another prominent example. In the past, it was one of Earth’s largest freshwater bodies. Between 1963 and 1990, however, it shrunk by an enormous 90 percent, partly due to reduced rainfall in the surrounding region.
In Bolivia, Lake Titicaca, the largest freshwater body in South America, has also faced climate change impacts. A prolonged drought between 2022 and 2023 devastated the lake, heavily affecting local communities and indigenous peoples who rely upon it for daily life. At its worst point, the enormous lake’s water level dropped by around 19 inches.
Read More: 5 Ancient Societies that Collapsed When the Water Ran Dry
Greenhouse Gases
Lakes and other water bodies are affected in many other ways by climate change. Researchers such as Yao also note that in colder climates, some lakes face fewer ice-covered days which can further enhance water loss. Climate change-induced extreme heat combined with pollution can also trigger problems like toxic algal blooms. Extreme weather also means many lakes are facing drastic fluctuations in their water levels, year after year.
The drying out of some bodies of water can become a source of climate change-fueling greenhouse gas emissions. A study published in 2024 found that Utah’s Great Salt Lake – which has lost around 70 percent of its water mass – released an estimated 4.1 million tons of CO2 and other greenhouse gases from dried out portions of the lakebed.
Past research suggested that climate change is only partly responsible for around 10 percent of of the Great Salt Lake’s decline, with water use and extraction from the rivers that feed it a primary culprit. But a recent paper suggests that increasing temperatures driving evaporation may be responsible for as much as one third of the lake’s recent decline in volume.
Read More: Is the Euphrates River Drying Up?
How Can We Manage the Water Decline?
These lakes and water bodies are just a few high-profile examples of a much wider problem, says Yao. His team published a study in 2023 that analyzed satellite data and found that more than 50 percent of the world’s large natural lakes and reservoirs have dried up, having shrunk in size since 1990. That’s due to a confluence of climate change, human use, including withdrawals for freshwater, agriculture, and industrial uses. Together, these water bodies are losing an estimated 22 gigatons of water every year, his study found.
“We were kind of surprised that about one quarter of the global population live in a basin with a large drying lake,” says Yao. “We find three major factors, that is warming climate, human over consumption and sedimentation are largely responsible for the observed total losses across the globe.”
“When people think about lake water decline, they maybe think the Aral Sea or Great Salt Lake, but we found that more than half of the largest water bodies in the world were drying based on nearly 30 years of satellite observations,” says Yao, adding that a different approach of water management is needed as well as efforts to tackle climate change.
“Integrated water management and including lakes is key to ensuring sustainability. If we think about the water supply as a system, from the river flow to lakes to groundwater, it could be a sustainable way to maintain healthy water levels,” he says.
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Sean Mowbray is a freelance writer based in Scotland. He covers the environment, archaeology, and general science topics. His work has also appeared in outlets such as Mongabay, New Scientist, Hakai Magazine, Ancient History Magazine, and others.
