More than half of world's large lakes and reservoirs drying up: Study

A new study reflects on the climate crisis and global warming as it reveals that more than half of the world's largest lakes and reservoirs are drying up.

The study which was published on Thursday in the journal Science highlighted that climate change and human activities are endangering lakes, which hold 87 per cent of the world's liquid surface fresh water. However, contemporary trends and sources of lake volume change are largely unknown around the world.

The study titled — Satellites reveal widespread decline in global lake water storage — examined the 1972 largest global lakes using three decades of satellite observations, climate data, and hydrologic models.

The study is aimed at finding statistically significant storage declines for 53 per cent of these water bodies over the period 1992–2020.

According to the study, the net volume loss in natural lakes is largely attributable to global warming, increasing evaporative demand, and human water consumption. Meanwhile, sedimentation is a dominant reason for storage losses in reservoirs.

'Lakes are in trouble'

The authors of the study noted that roughly one-quarter of the world's population resides in a basin of a drying lake, underscoring the necessity of incorporating climate change and sedimentation impacts into sustainable water resources management.

Balaji Rajagopalan, a professor at the University of Colorado Boulder and co-author of the paper, which appeared in Science, told news agency AFP: "Lakes are in trouble globally, and it has implications far and wide." 

"It really caught our attention that 25 per cent of the world's population is living in a lake basin that is on a declining trend," he said, indicating that around two billion people are impacted by the findings. Rajagopalan also said that unlike rivers, lakes aren't well-monitored despite their critical importance for water security.

The findings suggest that 53 per cent of lakes and reservoirs saw a decline in water storage, at a rate of approximately 22 gigatonnes a year. 

During the entire study period, 603 cubic kilometres of water were lost, which is 17 times the amount of water in Lake Mead, the largest reservoir in the United States. 

Rajagopalan said, "The climate signal pervades all factors." 

Fangfang Yao, who is the lead author and a visiting fellow at CU Boulder, added in a statement: "Many of the human and climate change footprints on lake water losses were previously unknown, such as the desiccations of Lake Good-e-Zareh in Afghanistan and Lake Mar Chiquita in Argentina."