วันศุกร์ที่ 10 กุมภาพันธ์ พ.ศ. 2555

Are the world's glaciers threatened by climate change? | Leo Hickman

A study published in the journal Nature has shocked researchers by considering that the Himalayas have lost any ice in the last decade. Leo Hickman, with your help, survey. Contact below the line, send your views

leo.hickman @ guardian.co.uk

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investigators are said to be surprised by a new study published in the journal Nature that found the largest mountain in the world , which extends from the Himalayas to the Tian Shan on the border between China and Kyrgyzstan, has lost none of the ice during the last decade.

Scientists had previously claimed that climate change is causing a net loss of ice and water from glaciers and ice caps that are in the Himalayas and other ranges mountains around the world. According to Damian Carrington report of the study, said:

The study is the first to examine all the world's ice sheets and glaciers, and was made possible by the use of satellite data. In general, the contribution of melting ice outside the two major ice of Greenland and Antarctica -. It is much less than previously estimated, with no loss of ice in the Himalayas and other high peaks of Asia responsible for most of the difference

thus allows this place a big question mark on the common claim that climate change is causing the melting of glaciers in the world? The photographs show how much the glaciers have retreated in the last century have become a totemic symbol of climate change. Glaciers are often described climate change as the "canary in the mine."

But as Carrington said, the claims for the melting of Himalayan glaciers have been controversial with the Intergovernmental Panel on Climate Change United Nations in 2010 admitting he was wrong declared a historical reports which would disappear by 2035 instead of 2350.

the Nature article comes with some important caveats and warnings, however:

"Our results and those from around the world shows that we waste a lot of water in the oceans every year," said Professor John Wahr of the University of Colorado [who led the study]. "People should be equally concerned about melting ice in the world, as they were before." study team concludes that among the 443-629bn tons of melt water is generally added to the world's oceans each year. This is the rise in sea level of about 1.5 mm per year, the team reports in more than 2 mm per year caused by the expansion of warming oceans.

Scientists are careful to point out that the low-altitude glaciers in the mountains of Asia - sometimes called the "third pole" - are definitely melting. Satellite imagery and reports confirm. However, during the study period from 2003 to 10 sufficient ice was added to compensate peaks ...

Wahr said that if it is crucial to a better understanding of the melting ice, the eight years of data is the relatively short period of time and the monsoon varies each year brings about changes in the mass of hundreds of billions of tons of ice. "It's very dangerous to take eight years and record to predict the next eight years, let alone the next century, "he said.

But your own thoughts and conclusions on the impact of climate change on glaciers? Should we worry if the glaciers melt?

citing figures to support your points, please provide a link to the source. I am particularly looking for links to data and documents that show the most comprehensive overview of the impact of climate change on glaciers, and especially the impact on humans and habitats, they melt. I will also invite stakeholders to participate in the debate, too. And later today I'll get back to my own verdict.


the Nature paper by Wahr, Jacob and others are accompanied by a "News and Views" article by Professor Jonathan Bamber, who is director of the Center for Glaciology of Bristol, Bristol University. It is entitled: "Climate change:. Glacier retreat in the spotlight "Here's an excerpt:

There are over 160,000 glaciers and ice caps around the world. Less than 120 (0.075%) had their mass balance (the sum of gains and losses of mass annual ice cover or ice) measured directly, and only 37 of them are there records extends over 30 years. Extrapolating from this small sample of observations of all glaciers and ice caps is a difficult task which inevitably leads to large uncertainties.

[The new] study based on satellite data for the gravitational field of Earth changes to address this problem. Their surprising results have implications for the overall contribution of glaciers to changes in sea level that occur in mountainous regions of Asia ...

First, the contribution of glaciers and ice caps (GIC) (excluding Antarctica and Greenland device CPG) at sea level was rising less than half the value of best estimates Recent obtained from the extrapolation of in situ measurements for 2001-05 (0.08 vs. 0.41 ± 1.1 mm yr-1). Second, losses for the high mountain areas of Asia including the Himalaya, Karakorum, Tian Shan, Pamir and Tibet - were negligible. In this case, the rate of mass loss was only 4 ± 20 gigatons per year (corresponding to 0.01 mm yr-1 of sea level rise), compared with previous estimates that were more than ten times greater. In a careful analysis, the authors discounted a possible tectonic origin of the huge gap, and it seems that this region is more stable than previously thought.

What is the significance of these results? Understanding and closing the budget of sea level (the relative contributions of thermal expansion of the change in mass and volume of the ocean) is crucial to test the predictions of future sea levels. Estimates of the future response to climate change are VSD General , based on what we know how they reacted in the past. A better estimate of past behavior, obtained by Jacob and colleagues, therefore, will result in better estimates of future performance.

Discussion the disappearance of Himalayan glaciers has been mired in controversy, partly because of basic errors, but also because of the scarcity of reliable data on past trends. Given his role as water supply for many people, which was a concern and an open question ...

Jacob and his colleagues have radically changed our understanding of recent changes in the overall volume of GIC and its contribution to rising sea levels. Now we need to know what it means for estimating their response in the future.


Last month, the Kathmandu-based Centre for International Development Integrated Mountain has published three reports provide an assessment "to day on climate change, snow and glacier melt in the Hindu Kush-Himalayan mountain in Asia ", which were defended by the Intergovernmental Panel on Climate Change Chairman Dr. Rajendra Pachauri:

These reports provide a new basis and the specific location information for the understanding of climate change on one of the most vulnerable ecosystems in the world.

The first report focused on the stability of glaciers in the region:

The HKH region is home to 30 percent of the world's glaciers has been called the "third pole". However, limited data on glaciers. A report, the state of glaciers in the Hindu Kush-Himalaya-presenting the results of a research project funded by Sweden three years conducted by ICIMOD, begins to fill important data gaps. Using remote sensing studies, the project could count the number of glaciers in the region, more than 54,000, and measure the floor area, 60,000 km.

Among the 54,000 glaciers, however, only ten were regularly examined to determine the net gain or loss of ice and snow (called the mass balance). This handful of studies show a loss of balance mass loss rate approximately double between 1980 and 2000 and 1996 and 2005. In the area of ??Mount Everest, the data show a marked acceleration of the mass loss of glaciers between 2002 and 2005. The glaciers seem to decrease in both the central and eastern Himalayas. Country studies have found that depletion of the glacier surface in the last 30 years was 22 percent in Bhutan and 21 percent in Nepal. Own glaciers of the Tibetan plateau are declining at a faster rate than the Himalayan glaciers, the rugged central, that have a higher coverage of residues, residues creates an insulating effect, melt slowly

The third report deals with the likely impacts if the glaciers melting in the region:

The increased melting of glaciers would limit the storage of water that provides natural extensions of snow and ice, and increase the risk of flooding glacial lakes. The mass loss of glaciers, reduction of the acceleration of the snow cover is expected ultimately to reduce supplies of water potential and hydropower. Changes in the seasonality of flows in river basins fed by meltwater from snow and ice are also planned. Drought is likely to affect larger areas and droughts that have to be more dependent on supplies of irrigation and water increasingly restricted, according to the authors. Flood risk is also rising to increasing climate variability.

This contrasts with an article published last October in the journal Scientific American (as indicated below the line, by @ BBCBias) suggesting that some glaciers provide less water than had been supported:

A growing number of studies based on satellite data and analysis of flow of the chemical have shown that much less surface water comes from melting glaciers previously thought. In Peru, Rio Santa, which drains the Cordillera Blanca mountain range, the contribution of glaciers appears to be between 10 and 20 percent. In the eastern Himalayas, which is less than 5 percent ...
Feeding the Himalayan glaciers in the major rivers of Asia: the Indus, Ganges and Brahmaputra in India, Pakistan and Bangladesh, and Yellow and Yangtze rivers in China. Early studies defined the amount of melt water in the basins of up to 60 or 70 percent. But reliable data on the amount of water from glaciers in the wild or in water have been difficult to develop. Satellite imagery can not provide such regular hydrometeorological observations and expeditions take much time, money and physical effort.

new methods, however, are improving the ability to study this and other mountain ranges away from the ice. Increasingly, scientists are discovering that the figures vary depending on the river, and even in different parts of the river.

"There has been much misinformation and confusion about it," said Peter Gleick, co-director of the California-based Pacific, Development Studies, Environment and Safety . "About 1.3 million people live in river basins to get some of the glaciers melted, but not all people who rely solely on water catchments, and not all the water from the river glaciers. Most comes from precipitation, "he said.

1:02 p.m.:

only say that at 14:10, Professor Jonathan Bamber, director of the Center for Glaciology of Bristol, will answer questions about what about the site. EnvironmentGuardian You can submit questions in advance here.

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