Scientists note that the Himalayan glaciers are sensitive to summer warming because both accumulation and ablation, or melting, primarily occur during the summer monsoon season. That means small increases in summer temperatures accelerate the melt while at the same time causing precipitation to fall as rain, which flows away, rather than snow.
Romance, exaggeration overlie a multitude of risks "Glaciers are a dynamic system, sort of a conveyor belt of ice from a higher elevation to a lower elevation," each part with its own individual behavior, he said. If everything is going well for a glacier, the mass it loses by seasonal melts at lower elevations is replaced by snowfall at higher elevations -- which then is packed down into ice and and carries its mass downhill over decades. Particularly in the eastern Himalayas, glaciers in lower elevations "are definitely seeing a warming," Armstrong said, while those above 18,000 feet appear far more resilient. Meanwhile, contrasting patterns of growth are evident in the western Himalayas among some 230 glaciers. Armstrong rattled off a handful of hyperbolic statements that have made their way into the mass media -- like that glaciers are melting faster in the Himalayas than anywhere else in the world, or that glacier melt will lead to catastrophic floods throughout Asia. There is little or no scientific evidence for some of these claims, he argues. While Armstrong chalks up exaggerations to the mysterious romanticisms that people apply to glaciers, he worries that those claims ultimately do a disservice to grasping the damage that the retreat of lower-elevation glaciers in the eastern Himalayan region will have on the wider region's water resources. "If a glacier can melt fast enough to cause a flood in Bangladesh, we're in bigger trouble than we thought," he said. Like other outsized claims, he said, "it's an example where there's not a lot of good data available, so if there's some emotional trigger ... people can say whatever hits them emotionally, and you can't prove them wrong." But understanding the area of what is called the Hindu Kush-Himalayan region is crucial. The remote mountain region encompasses about 15,000 glaciers -- sometimes referred to as the planet's third pole because it is the largest concentration outside of the Arctic and Antarctic -and sweeps through Pakistan, India, China, Nepal and Bhutan. The melted snow becomes the mother of headwaters for Asia's seven largest rivers, which in turn sustain some 1.5 billion people. 38