Monday, August 08, 2005

All World's Glaciers Could Melt, Latest Scientific Data Indicates

(A Story taken from ENS website)

ZURICH, Switzerland, August 5, 2005 (ENS) - Global warming caused by human activities may result in the complete disappearance of glaciers from entire mountain ranges, according to the latest update of a United Nations supported report issued once every five years. The World Glacier Monitoring Service warns that the greenhouse effect is leading to processes "without precedent in the history of the Earth."

"The last five-year period of the 20th century has been characterized by an overall tendency of continuous if not accelerated glacier melting," says the World Glacier Monitoring Service 1995-2000 edition of the Fluctuations of Glaciers report, complied with the support of the UN Environment Programme (UNEP).

"The two decades [from] 1980-2000 show a trend of increasingly negative balances with average annual ice thickness losses of a few decimetres," the report adds. "The observed trend of increasingly negative mass balances is consistent with accelerated global warming."

Analysis of repeated inventories shows that glaciers in the European Alps have lost more than 50 percent of their volume since the middle of the 19th century, and that a further loss of roughly one fourth the remaining volume is estimated to have occurred since the 1970s, the report states.

"With a realistic scenario of future atmospheric warming, almost complete deglaciation of many mountain ranges could occur within decades, leaving only some ice on the very highest peaks," it says.


The fractured and rapidly calving terminus of the surging Bering Glacier, Chugach Mountains, Alaska. October 1993 (Photo courtesy USGS)
The series "Fluctuations of Glaciers," prepared by the Service, continously publishes internationally collected, standardized data on changes in glaciers throughout the world once every five years. The Service is based at the Department of Geography University of Zurich.

The objective of the publication is to reproduce a global set of data which affords a general view of the changes, encourages more extensive measurements, invites further processing of the results, facilitates consultation of the further sources, and serves as a basis for research.

This standardized data set is presented as a working tool for the scientific community, especially concerning the fields of glaciology, climatology, hydrology, and quarternary geology.

Since the initiation in 1894 of a worldwide program for collecting standardized information on glacier changes, various aspects involved have changed "in a most remarkable way," the report says.

Concern increases that the ongoing trend of worldwide and fast if not accelerating glacier shrinkage at the century time scale is of non-cyclic nature.


Vulnerable to global warming, a glacier flows into the sea in North East Greenland. May 2002. (Photo courtesy European Space Agency)
While earlier reports anticipated a periodic variation in glaciers, "there is definitely no more question of the originally envisaged "variations périodiques des glaciers" as a natural cyclical phenomenon, the latest report states.

"Due to the human impacts on the climate system (enhanced greenhouse effect), dramatic scenarios of future developments – including complete deglaciation of entire mountain ranges – must be taken into consideration," it emphasizes.

The report says, "Such scenarios may lead far beyond the range of historical/holocene variability and most likely introduce processes without precedence in the history of the Earth."

The scientific opinion on climate change, as expressed by the UN Intergovernmental Panel on Climate Change (IPCC) and endorsed by the national science academies of the G8 nations, is that the average global temperature has risen 0.6 ± 0.2°C since the late 19th century, and that "most of the warming observed over the last 50 years is attributable to human activities."

Greenhouse gases emitted by the combustion of coal, oil and gas form a atmospheric blanket, trapping the Sun's heat close to the planet and raising the surface temperature.

(for my take on the most important climate change issues have a look at climate change action


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