NEW YORK — Climate change is “eating” the glaciers of the Himalayas, posing a grave threat to hundreds of millions of people who live downstream, a study based on 40 years of satellite data has shown.

The study, published Wednesday (June 19) in the journal Science Advances, concluded the glaciers have lost 1.5 feet of ice every year since 2000, melting at a far faster pace than in the previous 25-year period.

In recent years, the glaciers have lost about 8 billion tons of water a year. The study’s authors described it as equivalent to the amount of water held by 3.2 million Olympic-size swimming pools.

The study adds to a growing body of work that points to the dangers of global warming for the Himalayas, which are considered the water towers of Asia and an insurance policy against drought.

In February, a report produced by the International Center for Integrated Mountain Development warned the Himalayas could lose up to a third of their ice by the end of the century, even if the world can fulfill its most ambitious goal of keeping global average temperatures from rising only 1.5 degrees above preindustrial levels.

That goal, which scientists have identified as vital to avert catastrophic heat waves and other extreme weather events, is nowhere close to being met.

Average global temperatures have already risen by 1 degree in the last 150 years. Greenhouse gas emissions continue to climb. And scientists estimate we are on track to raise the average global temperature by 3 to 5 degrees Celsius by the end of this century.

Another study, published in May in Nature, found 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.

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.

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 kilometres, or more than 1,200 miles, of the Himalayas. THE NEW YORK TIMES