Peru water crisis 20 years early – ‘Already too late for most of the glaciers in the Andes’

By Stephen Leahy
27 December 2011
UXBRIDGE, Canada (Tierramérica) – The water supplied by the glaciers of the Cordillera Blanca, vital to a huge region of northwest Peru, is decreasing 20 years sooner than expected, according to a new study. Water flows from the region’s melting glaciers have already peaked and are in decline, Michel Baraer, a glaciologist at Canada’s McGill University, told Tierramérica. This is happening 20 to 30 years earlier than forecasted. “Our study reveals that the glaciers feeding the Río Santa watershed are now too small to maintain past water flows. There will be less water, as much as 30 percent less during the dry season,” said Baraer, lead author of the study “Glacier Recession and Water Resources in Peru’s Cordillera Blanca”, published Dec. 22 in the Journal of Glaciology. […] The tropical glaciers of the Andes Mountains are in rapid decline, losing 30 to 50 percent of their ice in the last 30 years, according to the French Institute for Research and Development (IRD). Most of the decline has been since 1976, IRD reported, due to rising temperatures in the region as a result of climate change. In Bolivia, the Chacaltaya glacier disappeared in 2009. Even in the colder regions of the Andes glaciers are in full retreat. Chile’s Centre for Scientific Studies reported this month that the Jorge Montt Glacier in the vast Patagonian Ice Fields receded one entire km in just one year. Historically glacial retreat is extremely slow: one or two km per 100 years. Melting glaciers around the world present some of the strongest evidence that global climate change is underway, said Lonnie Thompson of Ohio State University, the world’s foremost glaciologist. […] Until now it was widely believed that such declines would take place 20 to 30 years from now, allowing time to adapt to a future with less water. “Those years don’t exist,” said Baraer. […] “The northern Andes (in Peru) are close to being a desert. It is the water from the glaciers that has allowed people to survive here,” Baraer said. Last summer, researchers took measurements of the Río Santa’s water volume from the estuary where it reaches the Pacific all the way up to its sources in the Andes. They found that less than 20 percent of the water reaches the ocean now. “Eighty percent of the water from the Santa is already being used,” he said. Projections into the future reveal that in the coming decades some Río Santa sub-watersheds will have 30 percent less water – a serious challenge to the entire region when 80 percent of current volumes are already being used, Baraer stressed. “This water decline is guaranteed. The only question is how much and how quickly,” he said. There is already so much carbon in the atmosphere from the burning of fossil fuels that it is “already too late for most of the glaciers in the Andes,” he concluded.