Glacial Melt in the Himalayas: Real, but Not So Fast

Is glacier melt the biggest concern about climate change for Himalayan countries like India and China? No, says a new report from the National Academy of Sciences, coauthored by Nature Conservancy scientist Robert McDonald.

While glacial retreat is continuing in this region, the report says changes to monsoon rains and snowpack melt due to climate change will have more immediate impact on populations—and that these water stresses might eventually lead to political instability and even conflict unless countries begin to adapt.

I caught up with Rob McDonald to dive deeper into the report and its significance.


Q: Accounts of the rate of glacial retreat in the Himalayas have been widely variable—from dire predictions in 2007 to more moderate findings earlier this year. What’s the truth? And why has there been so much discrepancy?

Rob McDonald: We found that glacial melt is happening at a fast rate in the Himalayas, but it’s not happening faster here than elsewhere—the rate of melt is on par with other similar mountainous regions of the world. So, there’s nothing special about the Himalayan glaciers that’s making them melt faster.

More importantly, 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.

It’s been hard to get an accurate account of glacial retreat in the region for a few reasons. To get a sense of glacial retreat you don’t want to measure just surface area, you need to measure depth—that’s hard to do with satellite imagery. And the region is so remote that it’s difficult to get actual field samples—previous studies that said the glaciers were melting at a faster rate were based on measurements taken at low elevations, where glaciers are tending to melt faster.

But we’re starting to get better data, with new remote sensing studies.


Q: Will glacial melt have any impact on people living in this region?

Rob McDonald: High elevation towns and villages are impacted most directly by glacial melt. Glacial melt creates glacial lakes that can get blocked and then cause flooding. Called “glacial lake outburst floods” (GLOFs), these events are getting more frequent and have the potential to wipe out whole villages.

There have been various attempts to prevent GLOFs from happening: You have to remove the blockage and drain the lake. But this is a very steep mountainous region, and it’s hard to get heavy machinery there.

Addressing the problems these more remote, small villages face is certainly a political issue that the countries in this region will have to think about—how do you relocate people? Prevent loss of life? Compensate for lost livelihoods?


Q: The report looks specifically at the Indus and Ganges/Brahmaputra river basins, which include 7 countries and 800 million people. Water in the region is a big issue—what’s happening, and what role does climate change play?

Rob McDonald: 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).

We’re talking about the Indus River basin—which contains almost 200 million people and is the most water-stressed of the 3 big basins in this study. Bangladesh has the worst flooding problem already—due to monsoons and rapid snow melt—and a low economic capacity to cope.

So agriculture needs to get more efficient in the region. For instance, helping Pakistan get more efficient with their agriculture will help greatly as the Indus River basin changes.


Q: What about political stability—are “water wars” likely as populations grow and water supplies diminish?

Rob McDonald: Competition for natural resources and natural disasters most often cause political instability when there are other existing problems. Cimate change could certainly make a bad situation worse.

The good news is, there are already existing treaties that govern water use in the region. For instance, India and Pakistan have an international treaty on how water from the Indus River is used. The fact that there are existing treaties—and that cooperation has been the standard thus far—is a good sign.

The message of this report is: If governments of this region are smart, they will start to plan about how to manage water across borders in a world of altered climate.


Q: One thing we know about climate change is that we don’t know exactly how it’s going to play out. So how does a diverse region like the Himalayas—culturally, politically and geographically diverse—prepare for what’s next?

Rob McDonald: It’s true, we’re entering a new era of uncertainty. Climate change has the potential to significantly change monsoon rains, but its not clear yet if total rains will go up or down.

But there are ways to prepare. The committee recommends a few steps this region could take:

  • Monitoring: There’s not enough real-time monitoring of flows in these rivers and not enough sharing of data between countries.
  • Supply-side strategies: Ways to increase water storage or move water around. If climate change means dry periods will be even drier—which seems likely—then having ways to store water is important.
  • Demand-side strategies: Focus on efficiency of agriculture so less water is needed to produce crops.
  • Develop an integrated watershed management communication system. 

(Image: Tibetan prayer flags symbolizing sky, water, earth, fire and wind hang on the railing of a viewing stand that overlooks the rapidly receding Mingyong Glacier located in Yunnan Province, China. Source: Scott Warren.)

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  1. I, like many people am following glacial rivers in the Himalayan region.

  2. sooooooooooooooo boring

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