Researchers Warn Earth's Ice is Melting

by Danielle Knight

They also viewed gulls flying overhead, marking the first time they had ever been sighted at the pole.] (IPS) WASHINGTON -- Ice covering the Earth, from the polar caps to the Himalayas, is melting in more places and at a higher rate than ever before recorded, warns an environmental think-tank here.

This large-scale melting will raise sea levels, spark regional flooding, threaten water supplies, and alter the habitats of many of the world's plants and animals species, says the Worldwatch Institute.

As a whole, the world's glaciers are now shrinking faster than they are growing and losses from 1997 to 1998 were "extreme," according to the Swiss-based World Glacier Monitoring Service.

Scientists predict that up to a quarter of global mountain glacier mass could disappear by 2050. By the year 2100, only one-half of the ice could remain -- leaving large patches only in Alaska, Patagonia, and the Himalayas.

"Within the next 35 years, the Himalayan glacial area alone is expected to shrink by one-fifth, to 100,000 square kilometers," says Lisa Mastny, a researcher with Worldwatch, who has compiled scientific reports on ice-melting worldwide.

Some of the most dramatic reports come from the polar regions, she says, which are warming faster than the planet as a whole and have lost large amounts of ice in recent decades.

The Arctic sea ice has also thinned significantly since the 1960s. "Between this period and the mid-1990s, the average thickness dropped from 3.1 meters to 1.8 meters -- a decline of nearly 40 percent in less than 30 years," she says.

In the massive Antarctic ice cover of the South Pole, most of the ice loss has occurred along the edges of the Antarctic Peninsula, on the "ice shelves" that form when the land-based ice sheets flow into the ocean and start to float.

Three whole shelves have fully disintegrated and two more are retreating and expected to break up soon, having lost more than one-seventh of the combined 21,000 square kilometers since late 1998, according to Mastny.

Antarctica's vast land ice is also melting, but scientists disagree over how quickly.

One study estimates that the Western Antarctic Ice Sheet, the smaller of the continent's two ice sheets, has retreated at an average rate of 122 meters a year for the past 7,500 years and is in no danger of collapsing anytime soon.

But Mastny says other studies point to the fast-moving ice streams within the sheet that could speed up the melting, causing the sheet to break more rapidly.

Many mainstream scientists suspect that the enhanced melting is among the first observable signs of global warming caused by heat-trapping "greenhouse gas" emissions.

Most scientists believe that these gases -- produced through burning oil, natural gas, coal and other mostly carbon-based chemicals -- have been gradually warming Earth's atmosphere and altering its climate.

The average temperature of the atmosphere at the Earth's surface jumped dramatically in the past two decades, according to measurements taken by scientists world-wide. It reached a new high of 14.57 degrees Celsius in 1998, according to U.S. government studies.

If current record-breaking warming trends continue, average global temperatures could rise between one and 3.5 degrees centigrade by the year 2050, says a panel of expert scientists working with the United Nations.

Moreover, this loss of ice would affect more than the global climate, she adds. It would also "raise sea levels and flood coastal areas, currently home to about half of the world's people," she says.

Over the past century, melting ice caps and mountain glaciers have contributed to about one-fifth of the estimated 10-25 centimeter global sea level rise. The rest of the increase was caused by thermal expansion of the ocean as the Earth warmed.

"But ice melt's share in sea level rise is increasing, and will accelerate if the larger ice sheets crumble," says Mastny.

As mountain glaciers shrink, large regions that rely on glacial runoff for water supply could experience severe shortages, she adds. The Quelccaya Ice Cap, the traditional water source for Lima, Peru, is now retreating by some 30 meters a year -- up from only three meters a year before 1990 -- posing a threat to the city's 10 million residents, cautions Mastny.

In India, the Indus river reached record high levels in 1999 because of glacial melt, according to scientific reports.

Mastny says that this could be disastrous for northern India -- a region facing severe water scarcity where an estimated 500 million people depend on the tributaries of the glacier-fed Indus and Ganges rivers for irrigation and drinking water.

She explains that "as the Himalayas melt, these rivers are expected to initially swell and then fall to dangerously low levels, particularly in summer."

Rapid glacial melting can also cause serious flood damage, particularly in heavily populated regions like the Himalayas. In Nepal, for example, a glacial lake burst in 1985, sending a 15-meter wall of water rushing 90 kilometers down the mountains, drowning people and destroying houses.

The country's 50-hectare Imja Glacier is predicted to burst within the next five years, with similar consequences, she says.

Mastny warns that wildlife is already suffering as a result of the global ice melt -- particularly at the poles, where marine mammals, seabirds, and other animals depend on food found near the edge of ice.

"In Antarctica, the loss of sea ice, together with rising air temperatures and increased precipitation, is altering the habitats as well as feeding and breeding patterns of penguins and seals," she says.