Lakes may eventually disappear. This happens as they drain away through man-made barriers, fill up with sediment from rivers, or evaporate as the climate changes.
Bolivia’s second largest lake has vanished into thin air. In December, Lake Poopo became a dry salt pan and its largest lake – Lake Titicaca – is heading towards trouble, too. Recent research and new data suggest that lakes in other parts of the world may also be on their way out.
The combination of silting up and irrigation withdrawal from the Desaguadero River, which feeds Poopo, together with climate change and the extra warmth from current El Niño, were enough to finish this lake off. “Considering the size of the lake – 2700 square kilometres – this is quite an astounding event, with slim prospects of recovery,” says Dirk Hoffmann from the Bolivia Mountain Institute. “This event should serve as a real warning. Eventually, we can expect Lake Titicaca to go the same way.”
Air temperature has risen by around 0.7 °C in the Andes over the past 70 years and lakes are being evaporated faster than they are replenished. Lake Titicaca is close to a tipping point. Just 1 to 2 °C of atmospheric warming – which is expected by 2050 – could be enough to evaporate the top few metres, which would shut down the Desaguadero River and dry up all the water bodies that this river feeds. Such an outcome would be catastrophic for the 3 million inhabitants of Bolivia’s highlands, including the city of La Paz.
“If Titicaca stops supplying the Desaguadero River then the region will enter a new climate regime and the entire Andean Plateau will change from a benign agricultural area to an arid inhospitable area,” says Mark Bush, biologist at Florida Institute of Technology. “This happened during two prior interglacials and each time the dry event lasted for thousands of years.” It’s not just Andean lakes that are in trouble. Evidence from around the world suggests that lakes are warming, shrinking or disappearing, with huge impacts on ecosystems.
Picture Credit : Google