West Himalayan glaciers grew over last decade
The glaciers flowing between the towering peaks of the Karakoram range on the Pakistan-China border have grown in size in the last decade, according to new research.world Updated: Apr 17, 2012 01:07 IST
The glaciers flowing between the towering peaks of the Karakoram range on the Pakistan-China border have grown in size in the last decade, according to new research.
The impact of climate change on the ice in the greater Himalaya range has been controversial because of an unfounded claim by the United Nations' climate science panel over the rate of melting in the region. However the melting of vast volumes of ice into the sea in most other parts of the world has been clearly demonstrated.
In March, scientists showed far less ice was being lost across the Himalayas than had been estimated from sparse ground surveys on the remote slopes.
The new study shows that glaciers in one important part of the mountain range are growing. "We provide a detailed glacier-scale evaluation of mass changes in the central Karakoram," said Julie Gardelle, at CNRS-Université Grenoble, who led the research published in Nature Geoscience on Sunday. "In our warming world, there are regions of the Earth where, for a few years or decades, the atmosphere is not warming or is even cooling. So it is not really a big surprise that there are some regions where the temperature is not rising and the Karakoram may be one of those."
The scientists used 3D altitude maps obtained from satellites in 2000 and 2008 to track the changes in the glaciers. Prof Graham Cogley, of Trent University in Canada, who was not part of the research team, called the approach a "ground-breaking" advance.
"On most of the glaciers in the Karakoram it is not possible to be there," he said. "The roads end well short of the glaciers, and it can take days to trek to them. If you reach that point in spite of reluctant soldiers and eager terrorists, it might be physically impossible to get on to the glacier, which will be extremely crevassed and dangerous."
Global warming is causing the loss of more than 500bn tonnes a year of ice from the world's ice glaciers, but it is not yet understood why the Karakoram bucks that trend.
"It seems that, by a quirk of the atmospheric general circulation that is not understood, more snow is being delivered to the mountain range at present, and less heat," said Cogley.
He added that the valleys of the Karakoram are unusually steep sided, meaning that unpredictable snow avalanches add more ice to the glaciers than elsewhere.