Glaciers on the Himalayas are now melting about twice as fast as they used to do before. The event is being shown to the scientists now by the Cold War era spy satellite images. According to a study published on June 19, 2019 in the journal Science Advances, the Asian mountain range, which includes Mount Everest, has been losing ice since 2000 at a rate of about 1.0 per cent a year. Josh Maurer, a glacier researcher at Columbia University's Lamont Doherty Earth Observatory and lead author of the study, said, "The amount of ice (lost) is scary but what is much scarier is the doubling of the melt rate". The study revealed that the Himalayas, part of an area that is referred to as "The Third Pole" because it has so much ice, have only 72 per cent of the ice that was there in 1975. Compared to 4.3 billion tons (3.9 billion metric tons) a year between 1975 and 2000, it has been losing now about 8.3 billion tons (7.5 billion metric tons) of ice a year.
Maurer opined that the Himalayan melt doesn't contribute much to the sea level rise, because it is dwarfed by melting in Greenland and Antarctica. But study co-author Jorg Schaefer, a climate geochemistry professor at Columbia, said the loss of the ice means current and future disruptions of water supplies - both surges and shortages - for the hundreds of millions of people living in the region who rely on it for hydropower, agriculture and drinking water. Schaefer worried that "Disaster is in the making here". Until Maurer found once-classified 3D images from the United States (US) spy satellites that had been put online, the scientists lacked some critical data on ice in the Himalayas. Those images allowed Maurer to calculate how much ice was there on the Himalayas in 1975. He then used other satellite data to measure how much ice was there on the Himalayas in 2000 and then again in 2016.
Schaefer said that past research looked at individual Himalayan glaciers over short time periods. But this is the first to look at the big picture - 650 glaciers over decades. Scientists have looked at many possible causes for years for melting glaciers, including pollution and changes in rainfall. Schaefer said when the team was able to see trends using long-term data, they found the major culprit: "it's clear it's temperature and everything else doesn't matter as much". Maurer double-checked that conclusion by feeding the data into a computer model. It "predicted" the same type of ice melt that happened over the four decades.
The National Aeronautics and Space Administration (NASA) climate scientist Josh Willis, who wasn't part of the study, said it provided important confirmation of what scientists suspected and what models showed. Willis opined, "As a scientist it's nice to hear that we're right, but then again as a civilian it's sometimes a little scary to hear that we're right". The situation is really alarming for the people living in the countries like India, Nepal, Pakistan, Bangladesh and others of the region.
The writer is a retired Professor of Economics, BCS General Education Cadre. [email protected]
