How do you renew a lake

When lakes just disappear

The tire tracks on the bottom of Lake Poopó extend to the horizon. We follow them in an off-road vehicle. We don't see water anywhere: Bolivia's second largest lake has literally dissolved in the thin air of the Andean highlands.

The former lake bed is more than 3650 meters above sea level. Fishing villages, whose inhabitants a thousand years fed from the Poopó lake, are deserted. We drive past empty adobe houses. Vortices of dust dance around them in the warm breeze.

My guide Ramiro Pillco Zolá trudges over the salt pan to a dilapidated, half-buried boat. He tells of his childhood here by the lake: Before he left his home village of San Pedro de Condo, you could cross Lake Poopó in a rowboat. Pillco Zolá studied hydrology and climate change at Lund University in Sweden and did his doctorate. “What is going on here is no trivial matter,” he says. “Three decades ago, the lake's water covered an area of ​​3,000 square kilometers. It is difficult to regain that. "

Climate change is heating many lakes around the world faster than the oceans and the air. Together with human mismanagement, accelerated evaporation leads to increased water scarcity and the loss of habitats for birds and fish. "The traces of climate change can be found everywhere," says water ecologist Catherine O'Reilly of Illinois State University, who is jointly responsible for a study carried out by 64 scientists on lakes around the world. "But they manifest themselves a little differently with each lake."

Lakes on almost every continent suffer from the combination of overexploitation and increasingly extreme droughts. Satellite images show the shocking proportions. The African Lake Chad has been shrinking since the 1960s, only a narrow strip is left of it. There is less and less fish and water for agriculture. Internally displaced persons and refugees who are also dependent on the lake put additional strain on the scarce resources. In the Tai Hu Lake in eastern China, washed-out fertilizers and discharged sewage transport the cyanobacteria bloom, and the warm water further increases their growth. The bacteria threaten the drinking water supply of two million people. Lake Tanganyika in East Africa is so heated that the fish yields that feed millions of people in the four neighboring countries are at risk. In Venezuela, the water level behind the Guri reservoir with its important hydroelectric power station has fallen dramatically in recent years. In order to save electricity, the state had to cancel school classes.