From: Bruce Sterling []
Sent: Sunday, March 26, 2000 11:51 AM
To: Viridian List
Subject: Viridian Note 00143: Vanishing Glaciers

Key concepts: melting glaciers, freshwater shortages,
Worldwatch Institute

Attention Conservation Notice: Scary and depressing. Long, tedious, factual litany of rapidly vanishing natural features.

Source: Worldwatch Institute


"The Earth's ice cover is melting in more places and at higher rates than at any time since record keeping began. Reports from around the world compiled by the Worldwatch Institute (see data table below) show that global ice melting accelerated during the 1990s == which was also the warmest decade on record. (...)

"The Arctic sea ice, covering an area roughly the
size of the United States, shrunk by an estimated 6 percent between 1978 and 1996, losing an average of 34,300 square kilometers == an area larger than the Netherlands == each year.

"The Arctic sea ice has also thinned dramatically since the 1960s and 70s. 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. (...)

"The massive Antarctic ice cover, which averages 2.3
kilometers in thickness and represents some 91 percent of Earth's ice, is also melting. So far, most of the 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 begin to float. Within the past decade, three ice shelves have fully disintegrated: the Wordie, the Larsen A, and the Prince Gustav. Two more, the Larsen B and the Wilkins, are in full retreat and are expected to break up soon, having lost more than one- seventh of their combined 21,000 square kilometers since late 1998 == a loss the size of Rhode Island. Icebergs as big as Delaware have also broken off Antarctica in recent years, posing threats to open-water shipping. (...)

"Outside the poles, most ice melt has occurred in
mountain and subpolar glaciers, which have responded much more rapidly to temperature changes. (...)

"As mountain glaciers shrink, large regions that rely
on glacial runoff for water supply could experience severe shortages. The Quelccaya Ice Cap, the traditional water source for Lima, Peru, is now retreating by some 30 meters a year == up from only 3 meters a year before 1990 == posing a threat to the city's 10 million residents. And in northern India, a region already facing severe water scarcity, an estimated 500 million people depend on the tributaries of the glacier-fed Indus and Ganges rivers for irrigation and drinking water. But as the Himalayas melt, these rivers are expected to initially swell and then fall to dangerously low levels, particularly in summer. (In 1999, the Indus reached record high levels because of glacial melt.)"



"Arctic Sea Ice
Arctic Ocean
Has shrunk by 6 percent since 1978, with a 14 percent loss of thicker, year-round ice. Has thinned by 40 percent in less than 30 years.

"Greenland Ice Sheet
Has thinned by more than a meter a year on its southern and eastern edges since 1993.

"Columbia Glacier
Alaska, United States
Has retreated nearly 13 kilometers since 1982. In 1999, retreat rate increased from 25 meters per day to 35 meters per day.

"Glacier National Park
Rocky Mtns., United States
Since 1850, the number of glaciers has dropped from 150 to fewer than 50. Remaining glaciers could disappear completely in 30 years.

"Antarctic Sea Ice
Southern Ocean
Ice to the west of the Antarctic Peninsula decreased by some 20 percent between 1973 and 1993, and continues to decline.

"Pine Island Glacier
West Antarctica
Grounding line (where glacier hits ocean and floats) retreated 1.2 kilometers a year between 1992 and 1996. Ice thinned at a rate of 3.5 meters per year.

"Larsen B Ice Shelf
Antarctic Peninsula
Calved a 200 km2 iceberg in early 1998. Lost an additional 1,714 km2 during the 1998-1999 season, and 300 km2 so far during the 1999-2000 season.

"Tasman Glacier
New Zealand
Terminus has retreated 3 kilometers since 1971, and main front has retreated 1.5 kilometers since 1982. Has thinned by up to 200 meters on average since the 1971-82 period. Icebergs began to break off in 1991, accelerating the collapse.

"Meren, Carstenz, and Northwall Firn Glaciers Irian Jaya, Indonesia
Rate of retreat increased to 45 meters a year in 1995, up from only 30 meters a year in 1936. Glacial area shrank by some 84 percent between 1936 and 1995. Meren Glacier is now close to disappearing altogether.

"Dokriani Bamak Glacier
Himalayas, India
Retreated by 20 meters in 1998, compared with an average retreat of 16.5 meters over the previous 5 years. Has retreated a total of 805 meters since 1990.

"Duosuogang Peak
Ulan Ula Mtns., China
Glaciers have shrunk by some 60 percent since the early 1970s.

"Tien Shan Mountains
Central Asia
Twenty-two percent of glacial ice volume has disappeared in the past 40 years.

"Caucasus Mountains
Glacial volume has declined by 50 percent in the past century.

Western Europe
Glacial area has shrunk by 35 to 40 percent and volume has declined by more than 50 percent since 1850. Glaciers could be reduced to only a small fraction of their present mass within decades.

"Mt. Kenya
Largest glacier has lost 92 percent of its mass since the late 1800s.

"Speka Glacier
Retreated by more than 150 meters between 1977 and 1990, compared with only 35-45 meters between 1958 and 1977.

"Upsala Glacier
Has retreated 60 meters a year on average over the last 60 years, and rate is accelerating.

"Quelccaya Glacier
Andes, Peru
Rate of retreat increased to 30 meters a year in the 1990s, up from only 3 meters a year between the 1970s and 1990.

"Sources available upon request. For additional examples go to"

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