As glacial collapse driven by climate change is being cited as the cause of the massive floods in Nepal, an analysis found that as many as 100,000 glaciers are melting rapidly only in Asia's mountain regions.
According to CNN on the 28th (local time), Dan McGrath, a professor of geosciences at Colorado State University, said there are about 95,000 glaciers in Asia's mountain regions, and their total area is similar in size to Korea.
McGrath said, "These glaciers are losing mass at a very rapid pace," and "every year, the meltwater from glaciers in this region alone could submerge up to the top of New York's Empire State Building."
The Empire State Building is about 381 meters tall, excluding its spire. That means the volume of glacier loss each year in Asia's mountain regions is that large.
Experts say disasters like the recent floods in Nepal had already been anticipated and warn that even greater damage could occur. Jason Gulley, a geology professor at the University of South Florida who has studied glacial hydrology in Nepal and elsewhere, noted in an op-ed in The New York Times (NYT) that the melting glaciers in Nepal are like a "ticking time bomb."
Gulley has conducted six expeditions to Nepal's glacial regions over the past 20 years and said that since the 1990s, "glacial collapse" has already occurred dozens of times in the China-Nepal border area.
Glacial collapse refers to phenomena such as glacial avalanches, in which glacial ice crumbles like a snow slide; calving, in which large masses of ice break off; and rock-ice avalanches, in which bedrock and glaciers collapse together.
Gulley explained that if carbon dioxide emissions are not curbed, up to 75% of the glaciers remaining in Asia's high mountains could disappear by 2100 due to rising temperatures. As temperatures rise and glaciers melt, the resulting water can again form massive lakes, posing a potential threat to downstream areas nearby
He also said he has watched this process unfold in reality over the past 20 years. In 2005, a meltwater pond formed from the melting of the Ngozumpa Glacier in the Khumbu region of the Nepal Himalayas grew over about 20 years into a lake 750 feet (about 228 meters) wide.
He added that as glaciers shrink, flood risk could also grow, and that disasters larger than the recent floods in Nepal could occur in the future.