Glaciers near the southern South American country of Peru have shrunk by 40 percent in the past four decades, which has created a number of high-altitude lakes, Reuters reported.

Climate change is the cause for the melt-off, which has spawned nearly 1,000 new high-altitude lakes since 1980, the Peruvian government said Wednesday.

The glaciers in Peru are small compared to those found in the north and south poles, and are at a greater risk of disappearing. In addition, 70 percent of the world's tropical glaciers are found in Peru, and they are extremely sensitive to the warming temperatures associated with climate change.

In the coming years, 90 percent of the 2,679 glaciers could disappear, the country's water authority said, updating its report of glacier inventory that was last issued in the 1970s.

Those at greater risk of melting away are smaller than 1-square-kilometer, and spread over 19 snow-capped mountain ranges of the Andes.

Officials said 996 lakes have emerged in the Andes since the last count in 1980, which increases the total to 8,355.

They are the majority source of the country's drinking water.

The Peru Support Group, a U.K.-based non-profit that supports humanitarian and social causes in Peru, said the loss loss of the fresh water supply is also harmful to the country's economy.

About 70 percent of Peru's energy is hydroelectric, and supplies could be badly affected by a dwindling water supply. A 2006 World Bank study estimates reduced glacial melt will cost Peru's energy sector between $40 million to as much as $600 million.

While this potential threat to the available fresh water supply is pending, the glaciers have not always been only a source of good.

In 1970, at least 20,000 Peruvians were killed after an earthquake sent a glacier sliding into the highland town of Yungay, Reuters reported.

Peru is, appropriately, hosting the United Nations conference on global climate change in Lima in late November and December this year.