WARMING - Shrinks Peruvian glaciers

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Warming Shrinks Peruvian Glaciers

By Scott Wilson Washington Post Foreign Service Monday, July 9, 2001; Page A01

HUARAZ, Peru – A natural rhythm has dictated life in this high-mountain valley for centuries. The snow on the glaciers that loom along its eastern edge melts in the dry season, flowing down steep slopes and canyons and filling the Rio Santa with cool water. Each rainy season, the glaciers are again covered with snow that clings to the ageless icy summits until the sun starts the cycle over again.

Water streaming down for miles from the hundreds of glaciers in this stretch of the Andes known as the Cordillera Blanca, or White Range, drives the rural economy and does the village laundry. The water runoff moistens wheat and potatoes growing in neat patches along the mountain slopes. It lights the houses and huts with electricity generated by a hydroelectric plant on the river.

But now, hundreds of snow-tipped glaciers are retreating, and scientists say it is the direct result of a warming climate. The glaciers survive only where the air is cold enough to preserve ice, and the altitudes where this happens are climbing steadily. In the last three decades, Peru's glaciers have lost almost a quarter of their 1,225 square-mile surface, a loss of area roughly twice the size of Loudoun County.

The abundance of glacier runoff, visible as hillside streams and waterfalls cascading into the Rio Santa, has been a short-term boon to places like this. It has made possible plans to electrify remote mountain villages, turn deserts into orchards and deliver potable water to poor communities. In some mud-brick villages scattered across the valley, new schools will open and factories will crank up as the glacier-fed river increases electricity production.

At the same time, however, scientists warn that unless the Peruvian government begins to preserve the water by building an expensive network of reservoirs, towns like this that rely on glacier water during a five-month dry season will wilt without irrigation or electricity when the glaciers disappear. The national power supply, most of which is hydroelectric, will be crippled. And the melting has increased the threat of avalanches and mudslides, which have in the past killed thousands of people in these deep valleys.

"Industry is the interloper," said Benjamin Morales, the dean of Peru's glaciologists, who has studied the ice caps for decades. "And the consequence is that the glaciers will remain only in the highest mountains. The temperature was rising very slowly until 1980 and then" – he swept his arm up at a steep angle.

Representatives from more than 180 countries will gather July 16-27 in Bonn for a U.N. conference on global warming. The meeting is a follow-up to the 1997 Kyoto Protocol, which requires all signatories to make specific reductions in gases that cause global warming by 2012. The United States signed the agreement, but President Bush has renounced it, saying requirements that the United States reduce carbon dioxide and other pollutants by 7 percent from 1990 levels would be too costly.

For years, the debate over global warming has focused not so much on whether it exists, but what is causing it. Industry groups and their political supporters have argued that the warming is natural and inevitable, part of a cycle that has produced ice ages and periods of great heat. But environmentalists say man-made pollution is turning the atmosphere into a greenhouse by artificially sealing in heat, a view essentially endorsed by a recent National Academy of Sciences report requested by Bush.

Whatever the cause, Peru, home to eight of every 10 glaciers that lie within the tropics, is living with the consequences of a warming climate. Scientists say the country is an ideal venue for studying climate change because of the abundance of tropical glaciers; Morales calls them "the world's most sensitive thermometers," because they react to the smallest change in temperature. With 723 glaciers, the Cordillera Blanca has the most of any of Peru's 18 ranges.

The glaciers that loom over Huaraz, which sits at the base of a funnel created by the Cordillera Blanca and Cordillera Negra, 180 miles north of Lima, were formed more than a million years ago. For centuries, the ice has been protected by the steep parched slopes of the Cordillera Negra that have served as a windbreak against the warm breezes blowing off the Pacific Ocean.

But rising temperatures during the last century have accelerated in the past two decades, shrinking the ice caps so quickly that residents have watched a usually painstakingly slow geological process with their own eyes. Since 1967, when Peru began monitoring its glaciers, scientists estimate, the ice caps have lost 22 percent of their volume, enough to fill more than 5.6 million Olympic-size swimming pools.

When a glacier is large and healthy, snow that falls at high altitudes during the wet season accumulates. It melts during the dry season, but it is like interest in a bank account that provides water for the community but leaves the principal – the ice cap – largely intact. The glaciers are no longer recovering during the rainy season because of warmer weather, and the ice caps are being spent during the dry months.

"They are eating their capital," said Bernard Pouyaud, a scientist with the Institute of Research for Development in France, who has been studying glaciers in Bolivia and Peru for five years. Pouyaud said the average global temperature rose less than 1 degree Celsius over the last century, but he predicts a 3- to 5-degree increase over the next century. If that is true, Peru's glaciers would disappear.

When that will happen is a point of debate among scientists here and in the United States. Lonnie Thompson, an Ohio State University professor with long experience studying Peru's glaciers, has estimated that many of the ice caps could disappear in the next 15 years, although other scientists say that is implausibly fast.

But all agree that the glaciers are melting at a quickening pace. Marco Zapata, who has been studying the Cordillera Blanca glaciers for 31 years, runs the government's glacier office here.

The office has bounced around for decades between government agencies and private companies, always on the verge of collapse. Between 1996 and 1999, following the privatization of Peru's national power company, which was paying for the glacier office, Zapata's operation folded. When it was resurrected last year as part of the Institute of Natural Resources, Zapata could not believe what he found when monitoring resumed: The glaciers under observation had, in those four years, receded more than they had in the previous two decades.

The weather phenomenon known as El Niño, an unseasonable warming of the eastern Pacific off the coast of Peru, is the culprit. Named by the Spanish conquistadors for its arrival at Christmas, El Niño ("the child") used to appear every few decades. But since 1980 it has appeared with far more frequency and intensity, speeding the glaciers' steady retreat up the mountains. Many scientists blame this phenomenon on atmospheric disruption caused by pollution.

About a half-million people live in this high valley where, at dusk, clouds skim so low over hilltop stands of trees they seem to graze them. In the chilly evenings, the dry air fills with the spicy smell of burning wood fires and an absurdly bright moon flashes off the distant whiteness of the glaciers.

One recent morning, Zapata set off for his monthly inspection of a rainfall monitor on a glacier. Winding in a pickup truck through a vast, scrub-filled valley formed more than a million years ago by retreating glaciers, Zapata arrived at the foot of the Huarapasca glacier and climbed above 15,000 feet to a peak where his work waited. A crystal clear blue-green lagoon had formed at the foot of Huarapasca, an ominous sign since the lake means that the "tongue" of the glacier is in retreat.

To the east stretched the Huayhuash range. Much closer to the south sat Pastoruri, a glacier that Zapata predicts will be gone in 15 years. Less than five years ago tourists had to walk about a half-mile to step on the glacier. Today the hike is almost twice that long.

Pastoruri's retreat is taking with it the livelihood of a community, whose residents work in the cluster of kiosks that serve coca tea to tired hikers and provide mule rides to the glacier. Last month, taking advantage of an administrative lapse, the community essentially took control of what is a national park around the two glaciers. On that day, several men who rent mules and horses would not allow Zapata to go to the glacier in his truck, even though his agency had built the road to monitor its retreat.

Eleuterio Chavez, 36, who supports five children and a wife renting mules for less than $2 each, said he believed that Zapata's pickup would hasten the glacier's demise. "Without the glacier," Chavez told him, "We have nothing."

Zapata and other scientists say that in addition to the long-term threat of no water during the May-September dry season, there is an imminent problem – the instability that rapid melting brings to the glaciers. Glaciers usually melt into the rock, filling in fissures with water that expands and freezes when the temperatures drop. What scientists fear is that, with increased melting, more water and larger ice masses are pulling apart the rock and making the ice cap above more susceptible to the frequent seismic tremors that rock the area.

In May 1970, a small earthquake triggered an avalanche that broke a series of glacier lagoons, sending ice and frigid water shooting down through valleys at more than 250 miles per hour. The death toll reached 18,000 people and the town of Yungay, 25 miles north of here, was destroyed.

The longer-term threat is that once the glaciers disappear, thousands of towns like Huaraz will be without water for agriculture or power during a dry season. So far, two glacier lagoons have been reinforced with concrete walls fitted with valves so they can be tapped during dry months to preserve the Rio Santa flow, which drives the turbines at the Canon del Pato power plant to the north.

But Morales and others say the government must enlist private industry to help build many more natural reservoirs, and many of those will be located in dangerous seismic zones that will be expensive to build if they are to withstand earthquakes.

Zapata and other Peruvians who study glaciers say the government must begin spending money to study the problem in more detail. The scientists have no access to radar to measure glacier volume, no aerial photography that would determine the extent of the retreat. Satellite photos are useless because the scale is too small. Several international scientific missions are studying glaciers, which Peru's scientists welcome, but they say additional resources and more outside advice are needed.

"We need to know how fast these things are disappearing and where the threat is the greatest," Morales said.

In the meantime, the melting has meant a bounty of public works and development projects for Huaraz and its surrounding villages. One in three residents of Ancash state, of which Huaraz is the capital, do not have electricity and there are 310 pending requests from villages to join the power grid. About 15 percent of Ancash residents do not have running water.

Two enormous irrigation projects, both tapping into the flush Rio Santa, are under construction. One will use Cordillera Blanca glacier water to irrigate the western slopes of the Cordillera Negra. The other will flood the hills of neighboring La Libertad state, bringing water to more than 150,000 acres and transforming desert into asparagus farms. When complete in 2004, the project is expected to benefit more than 164,000 families who will work in the fields.

"This is allowing us to provide the basic blocks for development to many towns around here," said Zena Elias, an engineer with the government's National Fund for Compensation and Social Development. "This river just continues to rise."

© 2001 The Washington Post Company

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