Climate change threatens Latam water supply -WBank

Global warming is drying up mountain lakes and wetlands in the Andes and threatening....

  Global warming is drying up mountain lakes and wetlands in the Andes and threatening water supplies to major South American cities such as La Paz, Bogota and Quito, World Bank research shows. The risk is especially great to an Andean wetland habitat called the paramo, which supplies 80 percent of the water to Bogota's 7 million people. Rising temperatures are causing clouds that blanket the Andes to condense at higher altitudes. Eventually this so-called dew point will miss the mountains altogether, said World Bank climate change specialist in Latin America, Walter Vergara. "We're already seeing a drying up of these mountain lakes and wetlands. We're seeing that the dew point is going up the mountain," he said of the World Bank-funded research at Colombia's Institute of Hydrology, Meteorology and Environmental Studies. "(Clouds) are being driven up the mountain by climate change, and at some point will leave the mountain altogether." The World Bank will publish details later in the year, Vergara said in a telephone interview on Friday. Glacier melting, also caused by climate change, could hit water supplies to Quito and hydropower in Peru. Vergara was lead author of World Bank research published last month that found Ecuador would have to spend $100 million over the next two decades to cope with glacier retreat -- by for instance drawing drinking water from the Amazon basin. Glaciers act as a regulator, providing a water supply during dry periods, when they melt, and absorbing water during wet periods. "When you get rid of the glaciers you lose the water regulation. There'll be a less predictable water supply, and you won't have water at all at certain times of the year," said Vergara. Several glaciers, such as Ecuador's Cotacachi, have already disappeared, and most small, tropical Andean glaciers would be likely to disappear within a generation, providing an early glimpse of upcoming climate change consequences, the report said. The disappearance of the paramo would pose an even more serious problem than glacier retreat because more people depend on it for water, Vergara said.