January 7th, 2021, by Tim Radford
The Caspian Sea stands to be at least nine metres lower later this century.
The Caspian Sea’s decline means a climate-led water crisis for at least five Asian nations as inland seas dry up.
LONDON, 7 January, 2021 − The Caspian Sea − the world’s largest lake − is about to go down in the world. And with it could go the fortunes of some of the people of at least five nations. New research suggests that the Caspian Sea, already getting lower at the rate of several centimetres a year, is to go into even faster decline: later this century, it could be nine metres lower than it is now. Or even 18 metres lower.
Infographic showing the effects of water level change in the Caspian Sea area. (Naturalis)
German and Dutch scientists say the water level of the Caspian Sea, a land-locked lake with very salty water straddling Europe and Asia, has been dropping several centimeters per year since the 1990s. But that decline is accelerating at a pace that puts the 100 million residents in countries ringing the Caspian Sea at risk, according to a study published in the journal Communications Earth & Environment.
“If the North Sea would drop two or three meters, access to ports like Rotterdam, Hamburg and London would be impeded,” warned Dutch geologist Frank Wesselingh of the Utrecht University. “Fishing boats and container giants alike would struggle, and all the countries on the North Sea would have a huge problem.”
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Dec. 24, 2020
Global warming will not only cause sea levels to rise but lakes to shrink, a team of Dutch scientists warned this week. As a case in point, they predict a catastrophic drop in water levels in the Caspian Sea – presently the largest lake in the world – by the century’s end.
“Many people are not even aware that an inland lake is dramatically shrinking due to climate change, as our models indicate,” stated co-author Matthias Prange of the MARUM - Center for Marine Environmental Sciences at the University of Bremen, writing in Communications Earth and Environment. Which means countries are starting to think how to adapt to rising seas and creeping loss of low-lying coastland, but they’re not considering a decline in lake water levels.
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Credit: Naturalis
The water levels of the Caspian Sea will be 9 to 18 meters lower than they are now, German and Dutch researchers calculate. In the Nature-journal
Communications Earth & Environment they urge the world to act.
Coastal nations are rightly worried about a sea level rise, but in the countries around the Caspian Sea over a hundred million people are facing the opposite problem: an enormous drop in sea level. Technically, this sea is a land-locked lake, but it is the largest on the planet (371.000 km2), and quite salty.
The largest lake in the world is getting smaller every year, though. Since the 90 s, the water level has been dropping a few centimeters every year. This drop will accelerate during the upcoming decades, scientists from the German universities of Gießen and Bremen calculated, together with Dutch geologist Frank Wesselingh.