Himalayan glaciers will shrink by almost 10 percent, even if temperatures hold steady

Science Daily: Come rain or shine, or even snow, some glaciers of the Himalayas will continue shrinking for many years to come.

The forecast by Brigham Young University geology professor Summer Rupper comes after her research on Bhutan, a region in the bull's-eye of the monsoonal Himalayas. Published in Geophysical Research Letters, Rupper's most conservative findings indicate that even if climate remained steady, almost 10 percent of Bhutan's glaciers would vanish within the next few decades. What's more, the amount of melt water coming off these glaciers could drop by 30 percent.

Rupper says increasing temperatures are just one culprit behind glacier retreat. A number of climate factors such as wind, humidity, precipitation and evaporation can affect how glaciers behave. With some Bhutanese glaciers as long as 13 miles, an imbalance in any of these areas can take them decades to completely respond. "These particular glaciers have seen so much warming in the past few decades that they're currently playing lots of catch up," Rupper explains.

In fact, snowfall rates in Bhutan would need to almost double to avoid glacier retreat, but it's not a likely scenario because warmer temperatures lead to rainfall instead of snow. If glaciers continue to lose more water than they gain, the combination of more rain and more glacial melt will increase the probability of flooding -- which can be devastating to neighboring villages.

"Much of the world's population is just downstream of the Himalayas," Rupper points out. "A lot of culture and history could be lost, not just for Bhutan but for neighboring nations facing the same risks."...

The glacial lakes of Bhutan, NASA image