From: Bruce Sterling [email@example.com]
Sent: Sunday, March 26, 2000 11:51 AM
To: Viridian List
Subject: Viridian Note 00143: Vanishing Glaciers
Key concepts: melting glaciers, freshwater shortages,
Attention Conservation Notice: Scary and depressing. Long, tedious, factual litany of rapidly vanishing natural features.
Source: Worldwatch Institute
"MELTING OF EARTH'S ICE COVER REACHES NEW HIGH by Lisa Mastny
"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 thesize 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 2.3kilometers 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 inmountain and subpolar glaciers, which have responded much more rapidly to temperature changes. (...)
"As mountain glaciers shrink, large regions that relyon 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.)"
"TABLE 1: SELECTED EXAMPLES OF ICE MELT AROUND THE WORLD
"Arctic Sea Ice
"Greenland Ice Sheet
"Glacier National Park
"Antarctic Sea Ice
"Pine Island Glacier
"Larsen B Ice Shelf
"Meren, Carstenz, and Northwall Firn Glaciers
Irian Jaya, Indonesia
"Dokriani Bamak Glacier
"Tien Shan Mountains
"Sources available upon request. For additional examples go to http://www.worldwatch.org/alerts/000306t.html"
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