If not yet walking across a glacier, you might want to boot right away. The world’s high -mountain glaciers are melting faster than scientists once thought; as of 2015, nearly 300 billion tons of ice have been lost annually. If this melting continues, much could be lost by the middle of the century, according to a comprehensive new study today.
Researchers in Canada, France, Switzerland, and Norway have collected 20 years of satellite images taken from a special camera on a NASA satellite called Terra. The device, called ASTER, for the Advanced Spaceborne Thermal Emission and Reflection Radiometer, took images of more than 210,000 glaciers around the world, photographing each with two different lenses to create three-dimensional visions in their forms above. Excluded from the study were the many ice sheets that make up Greenland and Antarctica, which were studied by other teams of scientists.
The new analysis, published today on journal NATURE, found that between 2000 and 2004, glaciers lost 227 billion tons of ice per year. But between 2015 and 2019, this increase increased to 298 billion tons per year, a change explained by the study’s authors in warmer temperatures and increased rainfall. Taken, that melted water flowing into rivers and into the ocean represents about one -fifth of the observed sea level rise over the past 20 years.
And the problem isn’t just sea level rise, even if that’s a significant issue, that threatens the well -being of residents. coastal countries such as Indonesia, Bangladesh, Panama, Netherlands, ug how many parts of those United States. In some regions of the earth, millions of people rely on snow for clean water; in years when there is not much snow, glaciers offer a backup source of water. That is true in parts of the Andes, Himalayas, and Alaska. “It provides cool, plenty of water for many systems around the planet,” he added Brian Menounos, professor of World Sciences at the University of Northern British Columbia and co-author of the new study. “If the glaciers are gone, you don’t have that buffering capacity anymore.”
Menounos said previous studies of glacial melting have taken the smallest dimensions of both space and time, which brings some strength about how much glaciers are actually shrinking. By using detailed satellite imaging, he says, “We have shown that in our estimation, we have reduced uncertainty.” To beat the numbers for all 211,000 glaciers, it would require a University of Northern British Columbia supercomputer that runs almost full time a year.
The new analysis provides a dire warning about the future, however Jonathan Bamber, a professor of geographical science at the University of Bristol who was not involved in the study. “This is the most comprehensive, detailed, and thorough analysis of global ice mass loss in the 21st century ever made,” he wrote in an email to WIRED. “The level of detail of the results allows us to see changes in individual glaciers around the world for the first time.”
Bamber said the analysis shows whether if the trend continues, some low -mountain regions will lose their glaciers by 2050. “While the results and work are impressive, the headline message is embarrassing,” Bamber continued. “Glaciers are about to erupt, with profound impacts for water resources, natural hazards, rising sea levels, tourism, and local livelihoods.”
The study’s authors agreed with the analysis, and Menounos said some areas, such as the Cascades and Montana’s Glacier National Park, may be ice-free by mid-century. “See them while you can,” he urged.