Melting Andean Glaciers Could Leave 30 Million High and Dry

One of the highest glaciers in South America, Chacaltaya is one of the first glaciers to melt due to climate change. Although the glacier is over 18,000 years old, it is expected to vanish this year.

"The greenhouse gases are the main driver," says Vergara. "The scientific community has a consensus - this is manmade."

Since 1970, glaciers in the Andes have lost 20 percent of their volume, according to a report by Peru's National Meteorology and Hydrology Service.

The Chacacltaya Glacier in May 2005 (Photo by Thomas Wilken)

With water supplies, agriculture, and power generation at risk, the World Bank and the funding agency Global Environment Facility are working together to develop adaptation strategies for local communities.

In addition, the World Bank signed an agreement this month with the Japanese Space Agency that will start providing advance data and high resolution images to better monitor Andes Glacier retreat.

Seventy percent of the world's tropical glaciers are in the high Andes Cordillera of Peru, Bolivia, and Ecuador.

Of the 18 currently existing mountain glaciers in Peru, 22 percent of the surface has been lost over the past 27 to 35 years, scientists warn.

Most of the smaller glaciers in the Andes Cordillera are expected to shrink within a generation. Computer modeling indicates that many of the lower-altitude glaciers could disappear during the next 10 to 20 years.

The Latin America and Caribbean region, in particular, is very vulnerable to significant climate impacts, says the

The latest report of the UN's International Panel on Climate Change, IPCC, which involves thousands of scientists from around the world, lists evidence from all continents and most oceans showing that many natural systems are being affected by regional climate changes, particularly temperature increases.

The water supply in the Andes region due to climate change is already taking place, says the IPCC report, and is predicted to worsen with time.

A World Bank sponsored video presented last December during the IPCC meeting in Bali, Indonesia documented the impact already being felt in Pucarumi, a small community in the foothills of the Peruvian Andes.

Felipe, a Pucarumi alpaca herder, has witnessed the recession of the life-giving Ausangate glacier every year. "This loss of snow means we receive less water," he says in the video. "This climatic factor is causing us great danger."

The animals do not have sufficient food and their wool is not growing as it once did "That forces the people to resort to synthetic fibers to weave hats, sweaters and scarfs," Felipe says.

His community can no longer can seed indigenous potatoes in fields located at lower levels, because sufficient water does not flow there any longer. "We must seed them to greater height. But every year that happens, also we have less earth in mountains, Felipe says. "In few years more, no longer we will have no place to seed these potatoes."

The farmers now are forced to use fertilizing chemistries to cultivate "improved" potatoes. "We needed money to buy these fertilizers, but before it was different," Felipe explains. "We could use dung of the corral."

"All the community is worried," he says. "We do not know what to do or what to say about this chaos."

One of the functions of glaciers is to regulate water supply through runoffs during dry and warmer periods and store water in the form of ice during wet and colder periods. As glaciers retreat, this function will be lost, warns Vergara.

The entire range of the tropical Andes, home to over 30 million people and host to the vital global biodiversity, will be affected. As a result, shrinking water supplies will leave mountain communities, agriculture, and entire ecosystems high and dry.

Lima, Peru's capital city, has a population of about seven million. (Photo by Patrick Barry Barr)

Vergara says "water runoff in the glaciated basin that feeds El Alto has diminished as glaciers have retreated and water supply is now just about enough to meet demand during dry season."

Large cities in the region depend on glacial runoffs for their water supply. Quito, Ecuador's capital city, draws 50 percent of its water supply from the glacial basin, and Bolivia's capital, La Paz, draws 30 percent of its water supply.

The volume of the lost glacier surfaces of Peru is equivalent to about 10 years of water supply for Lima, Vergara says.

Power supplies also will be affected as most countries in the Andes are dependent on hydroelectric power generation. Peru gets 81 percent of its electricity from hydropower, Colombia generates 73 percent from hydropower, Ecuador is 72 percent hydro-dependent, and Bolivia, 50 percent.

Vergara estimates that the economic consequences of glacier retreat are enormous, running into billions of dollars for the power sector alone.

For example in Peru, the annual incremental cost to the power sector is estimated at US$1.5 billion, if rationing is allowed, or US$212 million, if a gradual adaptation scenario is implemented.

In any case, Peru will have to invest in additional power capacity, most likely based on burning fossil fuels, at a cost of about US$1 billion per gig watt installed, resulting in higher cost to end-users and another cycle of increased carbon emissions.

The World Bank and Global Environment Facility are supporting the development of adaptation plans prepared with the assistance of a multidisciplinary group that includes expertise in glaciology, remote sensing, agriculture, water and power supply, and rural development.

Some adaptation measures to climate impacts in the glaciarized basins of Bolivia, Ecuador, and Peru include development of alternative water supply sources, water demand management, and engineered water storage.

Diversification of energy supplies, shifts to alternative crops and development of advanced irrigation systems also can help Andean communities adapt to climate change.

Copyright Environment News Service (ENS) 2008. All rights reserved.