Melting Glaciers Threaten S America Ecosystem, Major Cities

by Abraham Lama

Scientists and environmentalists warn that a reduction of the ice mass in the portion of the Andes mountains located in tropical and subtropical regions will hurt water supplies in extensive areas of agricultural land in South America, as well as a number of cities, including the capitals of at least three countries -- Lima (Peru), La Paz (Bolivia) and Quito (Ecuador).

The glaciers of the Andes mountains in Peru account for a full 70 percent of the frozen surface area of the earth's tropical belt. They play a decisive role in the surrounding river system, and regulate the climate in the area under their influence.

The Cordillera Blanca, Peru's most important glacier system, has suffered an accelerated thaw over the past few decades, with approximately 50 million cubic meters of freshwater lost in one glacier alone in the past 67 years, according to scientific measurements.

"The reduction of ice in the Andes makes us tremble with concern, because it poses the threat of a steady decline of the water flowing in the rivers that are formed in the glaciers of the Andes," said Antoine Erout, with the French Institute of Andean Studies.

The glaciers retreat 20 to 30 meters a year, according to the Institute, which in coordination with Peru's National Institute of Natural Resources is monitoring and studying the evolution of the glaciers in the Cordillera Blanca.

"Since 1932, snowy areas as big as one-and-a-half kilometers in size have simply disappeared," he added.

The formation of lakes by the accelerated melting, which has surpassed the drainage capacity of rivers, and the resultant flooding have already caused several disasters, including the disappearance of an entire town, Yungay, in 1970, when all 20,000 residents were buried by a giant mudslide.

Erout pointed out that a number of new lakes had been created in the highlands due to the melting of the Cordillera Blanca glaciers.

"In late 1970, we counted 630 lakes. Now there are more than 700," said the expert. "At some point, those lakes will fill up and flood over, breaking down the natural dikes that now contain them, and triggering mudslides, which could mean a repetition of the tragedy of Yungay."

Benjamin Morales, president of the Andean Institute of Glaciology and Geoenvironment, urged the Peruvian government last year to anticipate the next El Nino weather phenomenon -- which will further accelerate the thaw -- by warning the population of the probable courses of the mudslides already taking shape.

"Global warming and deglaciation are without a doubt associated with the El Nino phenomenon, which in recent decades has had a considerable influence in catastrophic alterations of the climate in different parts of the world, especially along South America's Pacific coastline," said Erout.

Deglaciation is a phenomenon seen worldwide, linked to global heating, a process that has been studied by scientists since 1896.

According to Jeffrey Kiehl, with the United States National Center for Atmospheric Research, average air temperatures in the world have risen 0.6 degrees over the last 100 years.

Kiehl points out that in the past 12 years, scientists have observed an acceleration of global warming, partly due to the greenhouse effect, caused largely by emissions of ozone-depleting gases.

The United Nations-sponsored Intergovernmental Panel on Climate Change (IPCC) estimates that 60 percent of the global warming observed since 1850 has been caused by an increase in CO2 emissions produced mainly by the burning of fossil fuels.

The IPCC projects that the steady accumulation of greenhouse gases will drive the average temperature of the earth up by between one and 3.5 degrees over the next 100 years.

As prominent geographer and climate change expert Kurt Suplee points out, that change might seem slight, but the so-called Mini Ice Age, an extraordinary cold wave that peaked between 1570 and 1730, forcing many farmers in Europe to abandon their land, was caused by a change of just half a degree.