The world’s glaciers are melting faster than any time since records began, threatening catastrophe for hundreds of millions of people and their eco-systems.
According to the UNEP-backed World Glacier Monitoring Service (WGMS), data from nearly 30 reference glaciers in nice mountain ranges indicate that between the years 2004-2005 and 2005-2006, the average rate of melting and thinning are more than doubled. The details are revealed in the latest report from the World Glacier Monitoring Service and will add to growing alarm about the rise in sea levels and increased instances of flooding, avalanches and drought.
Based on historical records and other evidence, the rate at which the glaciers are melting is also thought to be faster than at any time in the past 5000 years, said professor Wilfried Haeberli, director of the monitoring service.
Most of Earth’s 160,000 glaciers have been slowly shrinking and thinning. Ice cores taken from mountains as far apart as the Andes in South America and the Himalayas in Asia have revealed how climate change is leading to a full-scale retreat of the world’s tropical glaciers.
The scientist, led by Lonnie Thompson of Ohio State University, present three lines of evidence pointing to a dramatic melting of glaciers in both the Andes and the Himalayas: a change in the chemical isotopes of the ice cores, the widespread retreat of glaciers and the uncovering of frozen plants that had been buried for thousand of years.
Prof Thompson and his colleagues spent two decades studying ice cores in South America, China, Africa and Tibet, analyzing the air trapped in the ice to build a history of climate change.
Professor Thompson said the research was based on nearly 50 scientific expeditions to seven mountain glaciers over the past three decades, including the Huascaran and Quelccaya ice caps in Peru, the Sajama ice cap in Bolivia and the Dunde and Puruogangri ie caps in China.
"We have a record going back 2,000 years and when you plot it out, you can see the medieval warm period [from 1000 to 1300] and the little ice age [from 1600 to 1850]. And in that same record, you can clearly see the 20th century and the thing that stands out is how unusually warm the last 50 years have been. There hasn't been anything like it, not even in the medieval warm period. The fact that the isotope values in the last 50 years have been so unusual means that things are dramatically changing."
The most dramatic evidence comes from 28 sites where the retreating ice has exposed plants that have been frozen and preserved for between 5,000 and 6,000 years by the glacier's base.
"This means that the climate at the ice cap hasn't been warmer than it is today in the last 5,000 years or more," Professor Thompson said. "If it had been, then the plants would have decayed."
The glaciers of Mount Kilimanjaro in east Africa and the Andes of Peru are melting so fast that they could disappear within 10 to 20 years.
The news follows other warnings that the Arctic ice fields is both shrinking in area and thinning in depth. A glacier in Antarctica has also retreated dramatically in the past decade.
A glacier in the Peruvian Andes, Qori Kalis, is losing as much ice in one week as it used to surrender in a year. As the Peruvian ice fields disappear, sources of irrigation and hydroelectric power will dry up. Other consequences include a more rapid rise in sea levels, speeding the flooding or even destruction of low-lying islands and coastal areas.
Glaciers are shrinking not only in area but also in thickness. In Alaska, they are losing an average of 6 feet (1.8 meters) of thickness a year.
Counting losses in both area and thickness, Mark Dyurgerov, an expert at the Institute for Arctic and Alpine research in Boulder, Colo., estimated that glaciers around the world are losing 22 cubic miles (92 cubic kilometers) of ice per year. That’s as much water as American’s homes, farms and factories use every four months.
Now, according to Lonnie Thompson of Ohio State University, the Quelccaya glacier in Peru has retreated 32 times faster in the past two years than in the 20 years from 1963 to 1983. Kilimanjaro’s ice fields have retreated by at least 80% since 1912. The icecap of Mount Kenya has shrunk by 40% since 1963. In 1972, in Venezuela, there were six glaciers; now there are only two. They too will melt within a decade.
“As a result of global warming, many tropical glaciers around the globe may disappear completely by 2020,” Professor Thompson told the American Association. “Apart from the dramatic impact on local communities it is also a potent sign that the Earth is undergoing enormous changes.”
“The glaciers are very much like the canaries once used in coal mines,” he said. “They are indicator of massive changes taking place and a response to the change in climate in the tropics.”
According to the UNEP-backed World Glacier Monitoring Service (WGMS), data from nearly 30 reference glaciers in nice mountain ranges indicate that between the years 2004-2005 and 2005-2006, the average rate of melting and thinning are more than doubled. The details are revealed in the latest report from the World Glacier Monitoring Service and will add to growing alarm about the rise in sea levels and increased instances of flooding, avalanches and drought.
Based on historical records and other evidence, the rate at which the glaciers are melting is also thought to be faster than at any time in the past 5000 years, said professor Wilfried Haeberli, director of the monitoring service.
Most of Earth’s 160,000 glaciers have been slowly shrinking and thinning. Ice cores taken from mountains as far apart as the Andes in South America and the Himalayas in Asia have revealed how climate change is leading to a full-scale retreat of the world’s tropical glaciers.
The scientist, led by Lonnie Thompson of Ohio State University, present three lines of evidence pointing to a dramatic melting of glaciers in both the Andes and the Himalayas: a change in the chemical isotopes of the ice cores, the widespread retreat of glaciers and the uncovering of frozen plants that had been buried for thousand of years.
Prof Thompson and his colleagues spent two decades studying ice cores in South America, China, Africa and Tibet, analyzing the air trapped in the ice to build a history of climate change.
Professor Thompson said the research was based on nearly 50 scientific expeditions to seven mountain glaciers over the past three decades, including the Huascaran and Quelccaya ice caps in Peru, the Sajama ice cap in Bolivia and the Dunde and Puruogangri ie caps in China.
"We have a record going back 2,000 years and when you plot it out, you can see the medieval warm period [from 1000 to 1300] and the little ice age [from 1600 to 1850]. And in that same record, you can clearly see the 20th century and the thing that stands out is how unusually warm the last 50 years have been. There hasn't been anything like it, not even in the medieval warm period. The fact that the isotope values in the last 50 years have been so unusual means that things are dramatically changing."
The most dramatic evidence comes from 28 sites where the retreating ice has exposed plants that have been frozen and preserved for between 5,000 and 6,000 years by the glacier's base.
"This means that the climate at the ice cap hasn't been warmer than it is today in the last 5,000 years or more," Professor Thompson said. "If it had been, then the plants would have decayed."
The glaciers of Mount Kilimanjaro in east Africa and the Andes of Peru are melting so fast that they could disappear within 10 to 20 years.
The news follows other warnings that the Arctic ice fields is both shrinking in area and thinning in depth. A glacier in Antarctica has also retreated dramatically in the past decade.
A glacier in the Peruvian Andes, Qori Kalis, is losing as much ice in one week as it used to surrender in a year. As the Peruvian ice fields disappear, sources of irrigation and hydroelectric power will dry up. Other consequences include a more rapid rise in sea levels, speeding the flooding or even destruction of low-lying islands and coastal areas.
Glaciers are shrinking not only in area but also in thickness. In Alaska, they are losing an average of 6 feet (1.8 meters) of thickness a year.
Counting losses in both area and thickness, Mark Dyurgerov, an expert at the Institute for Arctic and Alpine research in Boulder, Colo., estimated that glaciers around the world are losing 22 cubic miles (92 cubic kilometers) of ice per year. That’s as much water as American’s homes, farms and factories use every four months.
Now, according to Lonnie Thompson of Ohio State University, the Quelccaya glacier in Peru has retreated 32 times faster in the past two years than in the 20 years from 1963 to 1983. Kilimanjaro’s ice fields have retreated by at least 80% since 1912. The icecap of Mount Kenya has shrunk by 40% since 1963. In 1972, in Venezuela, there were six glaciers; now there are only two. They too will melt within a decade.
“As a result of global warming, many tropical glaciers around the globe may disappear completely by 2020,” Professor Thompson told the American Association. “Apart from the dramatic impact on local communities it is also a potent sign that the Earth is undergoing enormous changes.”
“The glaciers are very much like the canaries once used in coal mines,” he said. “They are indicator of massive changes taking place and a response to the change in climate in the tropics.”
© Steve Connor (Guardian News and Media Limited), UCS, Andy Rowell, Robert S. Boyd (Contra Costa Times), Pat Fryer, Wikepedia, GWArt, LiveScience
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