By Jayalakshmi K
Once again there is damning news against the Intergovernmental Panel on Climate Change (IPCC), this time from a study of glaciers in the Karakoram region of the Himalayas. It finds that the glaciers here are stable and snowfall is actually increasing adding to their bulk.
Even earlier, these glaciers have been a source of controversy showing a trend contrary to that experienced by glaciers elsewhere.
But the new study relies on improved resolution unlike those used earlier to show that the warmth of the region has been overestimated and the amount of snow underestimated.
The IPCC models use a coarse resolution which smoothes out elevation variation and was found unsuitable for the Karakoram region with high elevation variability, Sarah Kapnick, a postdoctoral researcher in atmospheric and ocean sciences at Princeton University told LiveScience.
By simulating climate down to an area of 50 square kilometres the team was able to match the observed temperature and precipitation cycles seen in the Karakoram region.
The Himalayan glaciers form the largest body of ice outside the polar caps and are the source of water for many rivers that flow across the Indo-Gangetic plains. Himalayan glaciers store about 12,000 km3 of freshwater.
Glaciers in the Himalayas are receding faster than in any other part of the world and at the present rate will disappear by 2035, the IPCC had warned in 2007.
A 2012 study by the University of Colorado using data from Grace satellite then showed that no ice was lost from the glaciers in the last decade, but yet the IPCC continued to insist on glacier melt in its 5th assessment report saying that the glaciers will shrink between 45% to 68% by 2100 according to the temperature rise on the planet surface.
While global warming leads to increased precipitation across the Himalayas, at Karakoram most of this extra moisture is received in the winter when westerly winds bring snow to the mountains, says the Princeton study.
Hence, snowfall is decreasing in the summer but increasing in the winter.
For central and southeast Himalayan regions most of the moisture delivered in summer by the monsoons falls as rain.
A recent study by Indian scientists too had shown that most of the glaciers in the region are stable.
Looking at changes to 2,018 glaciers in various Himalayan regions between 2001 and 2011, they had concluded that 1,700 were stable, showing the same surface area and no change of direction. The period of monitoring almost corresponds to the hiatus in global warming in the last decade, they noted.
The debate on glacier melt in the Himalayas will continue. Besides the IPCC, which has stuck to its original stance, other studies too have indicated loss of ice in the past decades.
What all of them insist is that melt or no, global warming is for sure.
Source: International Business Time