Now, Chacaltaya is fast disappearing, along with other Andean glaciers, a result of global warming, says Vergara. “The greenhouse gases are the main driver. The scientific community has a consensus—this is manmade.” Loss of the glaciers threatens the water supply of 30 million people.
With future water supply, agriculture, and power generation at risk, the World Bank and 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.
Lower Altitude Glaciers Could Disappear in 10 Years
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, an area equivalent to that of all the glaciers in Ecuador. 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 (SENAMHI).
Most of the smaller glaciers in the Andes Cordillera are expected to diminish within a generation. Modeling work and projections indicate that many of the lower-altitude glaciers could completely disappear during the next 10 to 20 years.
The International Panel on Climate Change confirms thermal changes are occurring in the earth’s environmental climate systems. IPCC’s latest report (2007) finds evidence from all continents and most oceans showing that many natural systems are being affected by regional climate changes, particularly temperature increases.
The Latin America and Caribbean region, in particular, is very vulnerable to significant climate impacts, says IPCC. Irreversible effects on key ecosystems are expected. The impact on the water supply and its availability is the one of the most significant effects that are already taking place in the region. Moreover, this impact is predicted to worsen with time.
A World Bank-sponsored video presented last year during the IPCC meeting in Bali Indonesia described the impact already being felt in Pucarumi, a small community in the foothills of the snow-capped Peruvian Andes. Felipe, an alpaca herder, has witnessed the recession of the life-giving Ausangate glacier every year. 'We are feeling the effects of climate change,' says Felipe. Without sufficient runoff from Ausangate that irrigates the pastures his animals cannot thrive. 'This loss of snow means we receive less water,” he said. “This climatic factor is causing us great danger.'
In addition to the difficulty of raising livestock on parched pastures, without the glacial runoff the land is running out of water to grow native potatoes, and the locals must resort to planting costly “improved potatoes with chemical fertilizers.”
Glacier Retreat and Economic Impact
One of the important functions of glaciers is the capacity to regulate water supply through runoffs during dry and warmer period while storing water in the form of ice during wet and colder periods. As glaciers retreat, this water regulation function will be affected and eventually lost. The area of this impact covers the entire range of the tropical Andes, home to over 30 million people and host to the vital global biodiversity. As a result, changes in water supply will have adverse effects for mountain communities, agriculture, and ecosystem integrity. 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.”
Impact on water supply to Andean cities
Rapid change in water supply will put both the human population and the food supply at risk, and higher water costs can ultimately impair the ability of these cities to maintain vibrant local economies. Large cities in the region are depending on glacial runoffs for their water supply. Ecuador's Quito draws 50 percent of its water supply from the glacial basin, and Bolivia’s La Paz, 30 percent. The volume of the lost glacier surface of Peru is equivalent to 7,000 million cubic meters of water that is about 10 years of water supply for Lima.
Impact on agriculture
Reduced water supplies during the dry season and an extended dry season have adverse effects on agriculture, as the people of the Pecarumi community are already experiencing.
Impact on energy
Most countries in the Andes are dependent on hydroelectric power generation: Bolivia 50 percent, Colombia 73 percent, Ecuador 72 percent, and Peru 81 percent. This contribution will be diminished in areas where water basins are glacier dependent.
The impact of Andean glacier retreat on the local economy is formidable. For example in Peru, the annual incremental cost to the power sector is estimated at US$1.5 billion (should rationing be allowed to occur), 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 thermal-based, at a cost of about US$1 billion per gig watt installed, resulting in higher cost to end-users (5), and of course that will set off the vicious cycle of increased carbon emissions. Vergara estimates that the economic consequences of glacier retreat are enormous, running into billions of dollars for the power sector.
Runoff from the glacierized basins of Andes is an important element of water budgets, assuring year-round flows for agriculture, potable water, power generation, and ecosystem integrity. The climate-change-induced change of this type and size that is associated with economic and social impacts is the early call for the need for adaptation. Some adaptation measures to climate impacts in glaciarized basins (Bolivia, Ecuador, and Peru) include:
- Development of alternative water supply sources, water demand management, and engineered water storage
- Diversification of energy supply; and,
- Shifting to alternative crops and developing advanced irrigation systems
The World Bank is working together with Global Environment Facility, to implement adaptation measures by:
- Supporting the detailed design of selected adaptation measures
- Implementing regional and strategic adaptation pilots to address key impacts of rapid glacier retreat on selected basins
- Supporting continuing observation and assessment of glacier retreat and the associated impacts on the region.
- Projects are being prepared with the assistance of a multidisciplinary group that includes expertise in glaciology, remote sensing, agriculture, water and power supply, and rural development.