No Time Left to Adapt to Melting Glaciers — Peak Water Has Already Come and Gone

Melt water from the glaciers of the Cordillera Blanca forms lagoons that in turn feed rivers and streams. Credit:Courtesy of Michel Baraer

Without sharp reductions in the use of fossil fuels, the impacts of climate change could come faster and beyond what humanity can adapt to — Lonnie Thompson, glaciologist

By Stephen Leahy

UXBRIDGE, Canada, Dec 27, 2011 (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.

When glaciers begin to shrink in size, they generate “a transitory increase in runoff as they lose mass,” the study notes.

However, Baraer explained, the water flowing from a glacier eventually hits a plateau and from this point onwards there is a decrease in the discharge of melt water. “The decline is permanent. There is no going back.” Continue reading