The World's Fastest-Melting Glaciers

Exploring the place where glaciers meet technology: Peruvians face huge environmental challenges.

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This segment is part of the Engineers of the New Millennium: The Global Water Challenge Special Report.

Transcript: Peru's Glacial Meltdown

Susan Hassler: The ancient Incas knew how to cope with extreme conditions in Peru. They cultivated crops on mountain terraces that would inspire vertigo in many a Great Plains farmer. Today's Peruvians are now also facing immense environmental challenges, especially in Lima, the second-largest desert city in the world. Sandra Upson visited Peru to explore the place where glaciers meet technology.

Sandra Upson: Standing on a bridge and staring down at the rapids of the Rímac River in the rainy season, it's hard to imagine that Lima is a desert.

Sandra Upson: A bridge support had collapsed under its force the day before, diverting traffic and clogging the city. Miguel Paredes, a native of Lima, began tracking the river's levels when its violent flow picked up.

Miguel Paredes: The average levels are probably at 60 or 70 square meters per second, the flow, and yesterday it was 127. So yeah, it's way higher than usual.

Sandra Upson: Flowing at double its usual rate, the river can wreak havoc on the people who use its waters. The water begins in lakes fed by glaciers in the Andes, in the mountain range known as Cordillera Huarochiri.

Sandra Upson: Benjamin Morales knows these mountains well. We're sitting on his porch in Lima, at a table stacked with his books and articles. The evening air is warm, but Morales is all about ice. Morales invented Peruvian glacier research in the 1960s, in the highland valley of Callejón de Huaylas.

Benjamin Morales: In the end of Callejón de Huaylas is the hydroelectrical plant of Cañon del Pato.

Sandra Upson: He's telling me about a time when glaciers were on the attack.

Benjamin Morales: And Callejón de Huaylas, there will be a lot of floods and ice avalanches, and so each flood that came, the water arrive to the hydroelectrical plant.

Sandra Upson: The hydroelectric authority asked Morales to go to the glaciers and stop the floods—a Peruvian spin on the story of the Dutch kid who stuck his thumb in a dike and saved Holland.

Benjamin Morales: We begin a new technology in the high mountains. We built more or less 25 dams, you know.

Sandra Upson: They built 25 dams to plug up valleys where water collects before spilling downhill onto the towns below.

Sandra Upson: That night, I boarded a sleeper bus from Lima to Callejón de Huaylas, to visit the glacier office and the glaciers.

Sandra Upson: Arriving in the mountain city of Huaraz the next morning, I have some time before my meeting at the glacier office. I start hiking up a mountain just outside Huaraz to a lake, Laguna Llaca. Donkeys, cows, and horses roam freely, as do a few villagers wearing wide-brimmed hats that shade their faces from the sun. And then ahead I see one of the dams Morales had built 40 years ago. It's a brick wedge driven into a gap between two slopes, a beige barricade to hold back the waters from what looks like a glimmering, peaceful lake. The water's surface reflects the glacier that looms above it, a snug white cap soft against the crags of a mountain.

Sandra Upson: Far below, I see a patchwork of tiny rooftops in a distant village.

Sandra Upson: These days, the glacier office plays a different role. Less concerned about the chaos of flooding, the office focuses on the opposite problem: not enough water. Lima lies in the Pacific basin, which contains less than 2 percent of Peru's water.

Marco Zapata: But in this zone lives the 70 percent of the population.

Marco Zapata: I am Marco Zapata Lujo; I am a geologist, engineer; I am the boss of the glaciological and water resources unit.

Marco Zapata: Okay, and you see here the Broggi Glacier, and in 2005 not a glacier anymore.

Marco Zapata: And so, there is another glacier, Yanamarei. And so we consider that in six years not glacier anymore on Yanamarei.

Sandra Upson: The list reads like an annual report on endangered species. Shrinking two times faster, six times—everywhere, signs that the hydrological cycle is changing. The glaciers are still there, but…

Marco Zapata: The question is, what will happen in future when the glacier will not be anymore?

Sandra Upson: The way Benjamin Morales sees it, there is a solution. It's not the solution pursued by the Peruvian government, which has been drilling massive tunnels through the Andes to drain water from the Amazon basin.

Benjamin Morales: We must to make new technologies for the use of water. Maybe don't make so much tunnels, maybe bring water from the sea.

Sandra Upson: Bring water from the sea and desalinate it, the way one mining company in southern Peru got water.

Michael LoCascio: The issues with reverse osmosis in seawater is that it takes a lot of energy.

Sandra Upson: Michael LoCascio is an analyst for Lux Research, in New York City, and he elaborates on Morales's point. Desalination takes energy—and therefore money—to push water through a membrane and separate salt ions from freshwater. In countries across the Middle East and elsewhere, the price has been worth it. In a year, the world desalinates as much water as the Amazon dumps into the Atlantic Ocean each week.

Sandra Upson: The ancient ice up in the mountains is a centerpiece of life in Peru. The glacier-fed rivers account for most of the country's electricity and its usable water, and the stunning white slopes of the Andes are a magnet for tourists. As glaciers melt, can Peru start using desalinated water from the ocean lapping against its coastline? The answer to that question could be the key to a prosperous future for Peru and its people. I'm Sandra Upson.