Local weather change is “consuming” the glaciers of the Himalayas, posing a grave risk to lots of of hundreds of thousands of people that reside downstream, a research based mostly on 40 years of satellite tv for pc knowledge has proven.
The research, printed Wednesday within the journal Science Advances, concluded that the glaciers have misplaced a foot and a half of ice yearly since 2000, melting at a far quicker tempo than within the earlier 25-year interval. In recent times, the glaciers have misplaced about eight billion tons of water a yr. The research’s authors described it as equal to the quantity of water held by three.2 million Olympic-size swimming swimming pools.
The research provides to a rising and grim physique of labor that factors to the risks of world warming for the Himalayas, that are thought-about the water towers of Asia and an insurance coverage coverage in opposition to drought.
In February, a report produced by the Worldwide Heart for Built-in Mountain Improvement warned that the Himalayas might lose as much as a 3rd of their ice by the top of the century, even when the world can fulfill its most formidable purpose of conserving world common temperatures from rising just one.5 levels above preindustrial ranges.
That purpose, which scientists have recognized as important to avert catastrophic warmth waves and different excessive climate occasions, is nowhere near being met. Common world temperatures have risen by one diploma already within the final 150 years. Greenhouse fuel emissions proceed to climb. And scientists estimate that we’re on monitor to increase the common world temperature between 3 to 5 degrees Celsius by the end of this century.
Another study, published in May in Nature, found that Himalayan glaciers are melting faster in summer than they are being replenished by snow in winter. In the warm seasons, meltwater from the mountains feeds rivers that provide drinking water and irrigation for crops.
The retreat of glaciers is one of the most glaring consequences of rising global temperatures. Around the world, vanishing glaciers will mean less water for people, livestock and crops.
In the Himalayas, the loss of glaciers poses two profound risks. In the short term, melting glaciers leave behind rock debris that creates dams, and if these debris dams burst, the resulting floods could destroy villages. In the long term, the loss of glacier ice means the loss of Asia’s future bank of water — a safeguard against periods of extreme heat and drought. Receding glaciers can also threaten the ecosystems they support, which can in turn affect communities in the region.
The latest study, led by researchers at the Lamont-Doherty Earth Observatory at Columbia University, relied on the analysis of satellite images of 650 glaciers across 2,000 kilometers, or more than 1,200 miles, of the Himalayas, including recently declassified United States spy satellite data. The researchers turned the images into 3-D models that showed changes in the area and the volume of the glaciers.
They found that from 1975 to 2000, glaciers across the region lost 10 inches of ice each year. Starting in 2000, the rate of loss doubled, to about 20 inches of ice each year. The study also concluded that while soot from fossil fuel burning is likely to have contributed to the ice melt, the bigger factor was rising temperatures. While temperatures varied across the vast mountain range, on average, they rose faster between 2000 and 2016 compared with earlier years.
For more news on climate and the environment, follow @NYTClimate on Twitter.