Hopefully by now you've digested the message that most of the glaciers in the Himalaya are indeed retreating even though some advancing (as are, by and large, glaciers around the world)—and that climate change is causing this. It's a big deal, with some very serious implications for future water supply throughout the parts of South Asia dependent on those glaciers.
That's all fine and good, but a new report from the National Academy of Sciences says that changes in the monsoon and the melting snowpack will be much more an immediate threat to the region.One of the report authors is a scientist with the Nature Conservancy, so naturally they've got an interview with him to publicize the research.
Here's the important take away, from Robert McDonald:
Glacial melt is not the biggest concern for most people when talking about the impacts of climate change to this region—changes to monsoon rains and snowpack melt could have bigger impacts. Monsoons and snowpack melt are annual occurrences, whereas glacial melt happens over decades. So the time scale is vastly different.
There are two main areas of concern: water for agriculture and water for growing urban populations.
By far, agriculture is the biggest user of water in these river basins—more than 80 percent of all water withdrawals are by agriculture. Urban use is growing—it’s actually increasing at a faster rate than agricultural use—but its still not nearly as high. Certainly the growth of cities will put even further strain on water use in the region. And many of these growing cities are along rivers, so flood and drought risk are significant. But agriculture is the big gorilla.
The places that will be hardest hit are the places that already have high water stress (a high fraction of available water already in use) and a low capacity of the community to adapt (ie, economic resources, water management plans).
As far as the monsoon is concerned, while we don't yet know with certainty the effect that climate change on the annual rains, research predicts a number of possibilities: The monsoon could be dragged out over the ocean, dropping water away from land; the intensity of downpours could increase, increasing the risk of flooding and somewhat ironically decreasing water availability if that water isn't captured; or, the monsoon could be delayed, and decrease in overall intensity.