Climate challenge
June 21, 2011
For centuries, the communities living at the foothills of the Himalayas have depended on the water that flows down from the mountains.
The region's many rivers are fed by melting snow and monsoon rains, eventually joining the powerful currents of the transboundary rivers Ganges and Brahmaputra, which go on to empty into the Bay of Bengal. The waters supply some 1.5 billion people in ten countries including India, Bangladesh, Pakistan and China.
But the flow of water down the slopes of the Himalayas is increasingly under threat. The dry and rainy seasons have become increasingly irregular - often lasting longer than usual and becoming harsher.
Unpredictable weather, unpredictable livelihoods
Georg Kaser, an expert on glaciers at the University of Innsbruck says a change in the intensity and duration of the monsoon rains impacts the climate system of the entire region.
"If there's suddenly more water in a mountain torrent, this affects the flow's entire environment and results in altered conditions," he says.
It's a problem that agronomists in northern Bangladesh are all too familiar with. The organization Practical Action focuses on seeking solutions, new farming methods and crops that will guarantee local populations a livelihood despite unpredictable weather.
Rice farming, for example, is hard hit by ground erosion and extended dry seasons, while pumpkin farming is better able to withstand such problematic conditions.
A question of diplomacy
One problem is that much of the water flowing through Bangladesh, one of the world's poorest countries, originates beyond its borders. The source of its main rivers is in India, which could turn off its neighbor's tap by building reservoirs, for example, leaving Bangladesh high and dry.
The two nations have been involved in political negotiations since decades. But not much has resulted from the talks yet – apart from the Ganges water-sharing treaty signed in 1996 by the prime ministers of Bangladesh and India. This established a 30-year water-sharing arrangement and recognized Bangladesh's rights as a lower-level riparian.
But it's far from an ideal solution to the problem. The state of the river in question is determined by the rainy season.
"The climate in the region is dominated by the monsoon," says Georg Kaser. "Summers are warm and wet, while winters are cold and dry."
"Once the snow has melted, the glacial melt begins in summer, while the monsoon arrives from the Bay of Bengal,” explains Marcus Nüsser, an expert on Southeast Asia and a professor of geography at the University of Heidelberg.
Researchers say the impact of climate change is evident in the region.
"We've observed change in the Himalayas, also in the volume of the glaciers," he said, adding that it meant the glaciers were actually melting away. But he says this is localized and not the case across the mountain range.
"Even though temperatures are higher and trends have been observed, it's hard to cite concrete figures in Asia as opposed to other regions in the world where glaciers are in part receding dramatically," he says.
Regional variations
In fact, in regions where monsoon oscillations have resulted in heavier rainfall – such as Karakoram in Pakistan – glaciers are actually advancing.
"Temperatures would have to rise a lot more before these glaciers melted," argues Georg Kaser.
In 2010, the Intergovernmental Panel on Climate Change (IPCC) was brought into disrepute for the erroneous claim that the Himalayas' glaciers would melt by 2035.
The claim was contained in a section of the IPCC's 2007 assessment report. Although the error was contradicted by the report's conclusions, which referred to an accelerating rate of glacial melting "throughout the 21st century," the damage to the IPCC's reputation for high standards of accuracy was undeniable.
An independent review of the IPCC chastised some of its procedures, but upheld the basic conclusions of its 2007 report, and their implications for the long-term water security of a region home to more than one-sixth of the world population.
Author: Klaus Esterluß (jp)
Editor: Sonia Phalnikar