Global warming is melting 18,000 Himalayan glaciers — the largest concentration of glaciers outside the great polar ice sheets. If the present melt rate continues, many of these glaciers will be gone by the middle of this century, disrupting the perennial water supply to hundreds of millions of people.

To explore this growing collection of glacier images from the “roof of the world” — including a must-see video made by mountaineer and filmmaker David Breashears, Founder and Project Leader of Glacier Research Imaging Project (GRIP) — go to the Asia Society’s “On Thinner Ice” website.

For some of the underlying science, see my November 2008 post, Another climate impact comes faster than predicted: Himalayan glaciers “decapitated.” It discussed an important paper by leading international cryosphere scientists, including American’s own Lonnie Thompson, “Mass loss on Himalayan glacier endangers water resources,” which concluded ominously:

If Naimona’nyi is characteristic of other glaciers in the region, alpine glacier meltwater surpluses are likely to shrink much faster than currently predicted with substantial consequences for approximately half a billion people.

The study notes that Naimona’nyi is the highest glacier (3.7 miles above sea level) “documented to be losing mass annually.” MSNBC reported:

Lonnie Thompson of Ohio State University and a team of researchers traveled to central Himalayas in 2006 to study the Naimona’nyi glacier, expecting to find some melting … But when the team analyzed samples of glacier, what they found stunned them …

In fact, the glacier had melted so much that the exposed surface of the glacier dated to 1944 …

“At the highest elevations, we’re seeing something like an average of 0.3 degrees C (0.54 degrees F) warming per decade,” Thompson said …

“I have not seen much as compelling as this to demonstrate how some glaciers are just being decapitated,” Shawn Marshall of the University of Calgary said …

“You can think of glaciers kind of like water towers, ” he said. “They collect water from the monsoon in the wet season, and release it in the dry season. But how effective they are depends on how much water is in the towers.”

The time to act is now.

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