On the Roof of Peru, Omens in the Ice

Retreat of Once-Mighty Glacier Signals Water Crisis, Mirroring Worldwide Trend

QUELCCAYA GLACIER, Peru -- In the thin, cold air here atop the Andes mountains, the blue ice that has claimed these peaks for thousands of years and loyally fed the streams below is now disappearing rapidly.

Mountain glaciers such as this are in retreat around the Earth, taking with them vast stores of water that grow crops, generate electricity and sustain cities and rural areas.

Farmers here say that over the past two decades they have noticed a dramatic decrease in the amount of ice and snow on their mountaintops. The steady supply of water they need to grow crops has become erratic.

"There is less water now. If there is no water, this land becomes a desert," said Benedicto Loayza, a 52-year-old farmer, standing under pear trees fed by channels dug on the mountain centuries ago to collect runoff.

Cuzco, a city of 400,000, has already resorted to periodic water rationing and started pumping from a river 15 miles away for its drinking supply. In Peru's capital, Lima, engineers have urged successive governments to drill a tunnel through the Andes and build big lagoons to ensure that the city's 8 million residents have water. Citing the expense, authorities have dawdled. Cities in China, India, Nepal and Bolivia also face drastic water shortages as the glaciers shrink.

"You can think of these glaciers as a bank account built over thousands of years," said Lonnie Thompson, one of the first scientists to sound the alarm, as he stood by the largest ice cap in the Andes. "If you subtract more than you gain, eventually you go bankrupt. That's what's in process here."

Thompson arrived at the blue-white face of the Quelccaya glacier this month after a two-day hike from the nearest road, climbing into the oxygen-thin air of 17,000 feet above sea level. Since he started his annual visits here in 1974, he said, the huge ice cap has shrunk by 30 percent. In the last year, the tongue of the ice has pulled back 100 yards, breakneck speed for a glacier.

He examined it as if it were a sick patient. The mountain of ice was pocked with holes where the surface had melted. A large chunk had broken off in March, crashing into the meltwater lake below and sending a flood wave into alpacas' lower grazing grounds. The face of the glacier, once frozen so perfectly that Thompson could identify the yearly snowfalls back 1,500 years, now sagged and dripped.

"It's not just a retreat," he said. "It's an accelerating retreat."

Since Thompson's first reports, he and others have confirmed a rapid recession of glaciers worldwide. Snows on Africa's Mount Kilimanjaro, extolled by Ernest Hemingway as "wide as all the world, great, high, and unbelievably white," will be gone within 14 years, Thompson estimates. Glaciers in the Alps, the Himalayas and throughout the Andes are also shrinking, he and other researchers have found.

The dramatic rise in carbon dioxide that has accompanied the industrial age has brought a spike in global temperatures. Scientists have found that the jump in temperatures is even greater in the upper atmosphere, where the glaciers reign on silent mountain peaks.

Glaciers store an estimated 70 percent of the world's fresh water. Water that falls as snow moves through the slowly churning ice and may emerge from the glacier's edge thousands of years later as meltwater. Humans have long depended on the gradual and faithful runoff.