From this Associated Press article that we found at the Atlanta Journal Constitution, writer Michael Casey tells us more about the study.
Those that do count heavily on glaciers like the Indus, Ganges and Brahamaputra basins in South Asia could see their water supplies decline by as much as 19.6 percent by 2050. China's Yellow River basin, in contrast, would see a 9.5 percent increase precipitation as monsoon patterns change due to the changing climate.
"We show that it's only certain areas that will be affected," said Marc Bierkens, an Utrecht University hydrology professor , who along with Walter Immerzee and Ludovicus van Beek conducted the study. "The amount of people affected is still large. Every person is one too many but it's much less than was first anticipated."
The study is one of the first to examine the impact of shrinking glaciers on the Himalayan river basins. It will likely further fuel the debate on the degree that climate change will devastate the river basins that are mostly located in India, Pakistan, Nepal, Bangladesh, Bhutan and China.
Scientists for the most part agree glaciers are melting at an accelerated rate as temperatures increase. Most scientists tie that warming directly to higher atmospheric concentrations of greenhouse gases such as carbon dioxide.
Some glaciers, such as in the Himalayas, could hold out for centuries in a warmer world. But more than 90 percent of glaciers worldwide are in retreat, with major losses already seen across much of Alaska, the Alps, the Andes and numerous other ranges, according to researchers in the United States and Europe.
Still, several of these outside researchers said the findings should reaffirm concerns that the region will suffer food shortages due to climate change, exasperating already existing concerns such as overpopulation, poverty, pollution and weakening monsoon rains in parts of South Asia.
"The paper teaches us there's lot of uncertainty in the future water supply of Asia and within the realm of plausibility are scenarios that may give us concern," said Casey Brown, an assistant professor of civil and environmental engineering at the University of Massachusetts.
"At present, we know that water concerns are already a certainty - the large and growing populations and high dependence on irrigated agriculture which makes the region vulnerable to present climate variability," he said.