A new study published this week in Science Advances听offers one of the most comprehensive views of what鈥檚 happening to the glaciers听in the Himalayas鈥攁nd what it means for the people who live below them.
, led by Joshua Maurer, a Ph.D. candidate at Columbia University鈥檚 Lamont-Doherty Earth Observatory, analyzed 40 years worth of satellite images of around 650 glaciers听across more than 1,200 miles听of India, China, Nepal, and Bhutan. One of the largest听ice loss studies to date (in both area and timespan), it not only confirms that climate change is the main contributing factor to glacial retreat in high-mountain Asia, but also reveals how fast rising temperatures are changing the face of the planet. According to the study, glaciers in the region have been losing the equivalent of more than a vertical foot and a half of ice each year since the turn of the millennia鈥攚hich is twice the rate of melting between 1975 to 2000.
鈥淧robably the most surprising thing [we found] would be the fact that we see such a similar amount of glacier melting across such a large and climatically complex region,鈥 says Maurer. 鈥淭hat highlights the fact that there鈥檚 an overarching climate force affecting all these glaciers similarly.鈥
In recent years, that鈥檚 looked like an average of 8 billion tons of water per year鈥攅qual to听3.2 million Olympic-size swimming pools鈥攆lowing out of the region, which presents a couple听of new problems: first, too much water, and then not enough. According to Maurer, as meltwater increases, glacial lake outburst floods (GLOFs), or catastrophic bursts of overflow from previously contained glacial meltwater, will start to be a serious threat. (One GLOF in Bhutan 听in 1994.听Nepal鈥檚 Imja Tsho, a glacial lake in the Khumbu Valley, was subject to an to reduce flood risk.) Then, as the glaciers continue to retreat, the water they provide to nearly 2 billion people听is听, and, eventually, disappear.听
Another study, conducted by the 听and published in , had similarly alarming claims: even if the entire world鈥檚 global emissions were net zero by 2050, one-third of the Hindu Kush-Himalaya region鈥檚 ice would still melt. If the world doesn鈥檛 reach net zero, we could see the loss of up to two-thirds of the ice in that region by 2100.听
In high-mountain听Asia, occasionally referred to as 鈥渢he third pole鈥 because听it contains the most ice in one region after the actual poles, the melting has gotten macabre.听On Everest, the bodies of dead climbers are melting out of the ice, on what to do with them. on the world鈥檚 highest peaks is also proving to be a biohazard problem, contaminating water sources as it thaws.听
Maurer says that despite the depressing news, we need studies like this to prepare ourselves for what鈥檚 coming.听
鈥淲ith climate change studies, it鈥檚 always bad news,鈥 he听says. 鈥淏ut they鈥檙e necessary so that we know what we can expect in terms of future change.鈥