The backlash over the recent revelation that the 2007 IPCC report included an erroneous alarm that the Himalayan glaciers could disappear by 2035 has been well-documented. Much of the concern flowed from the fact that the glaciers feed several major rivers in South Asia and Southeast Asia where millions of people live. General opinion now holds that while some glaciers are indeed receding, there is little chance that they will disappear anytime soon- and others are actually advancing. So where does that leave the water situation for the rivers and the people who depend on them?
“There has been too much focus on glaciers whereas there are other factors like precipitation and snowfall that affect the levels of waters in rivers downstream from the eastern Himalayas.” – Mats Eriksson, senior hydrologist at the Nepal-based International Centre for Integrated Mountain Development (ICIMOD)
Eriksson has been part of many studies on the water situation in the area. The BBC reports that according to a recent study for the World Bank, it turns out that only 5% of the river flows come from glacier-melt.
“…about 95% or more of the river flow is the result of rain and melting seasonal snow” – Richard Armstrong, UC-Boulder glaciologist and report co-author.
Precipitation like rain and snowfall will be affected by climate change, but no one is willing to say how much, when, or even whether those changes will mean higher or lower river levels.
According to Erikkson, “…there has been no consistent measurement of precipitation and temperature and there is a lack of proper studies.”
Scientists are continuing to study the effect of heat trapping aerosols on monsoon patterns and studying why some glaciers are receding and others are advancing. It seems, too, that precipitation pattern predictions based on climate models are proving variable and, in effect, unreliable. Add in the political ripples and geographical realities of the vast region and it becomes difficult to be certain of anything about the status of the glaciers or what the future holds for the rivers.
“Some countries in the region are not willing to share water-related data because they regard it as confidential. Since it is difficult to access them, proper studies on water availability remain a major challenge.” – Dr. Erikkson
In the end, what is certain is the uncertainty. The ripple effect of an erroneous prediction is that we will have to learn to live with a certain level of not knowing.