Himalayan glaciers are melting twice as fast now as they were before the turn of the century, according to a new study that relied on declassified Cold War-era satellite imagery.
The study, which appeared in Science Advances on Wednesday, is the latest indication that climate change is eating the Himalayan glaciers, threatening water supplies for hundreds of millions of people downstream across South Asia.
“This is the clearest picture yet of how fast Himalayan glaciers are melting over this time interval, and why,” said lead author Joshua Maurer, a doctoral candidate at Columbia University in New York.
Photo: AP / Joshua Maurer
Scientists combed 40 years of satellite observations spanning 2,000km across India, China, Nepal and Bhutan, and found that the glaciers have been losing the equivalent of 45cm of ice each year since 2000.
Many of the 20th-century observations came from declassified US spy satellite imagery.
The figure is double the amount of melting that took place from 1975 to 2000. Past research has found similar trends, but the latest work is bigger in its geographic and historic scope.
It concluded that rising temperatures are the biggest factor. Though temperatures vary from place to place, average temperatures were 1°C higher between 2000 to 2016 than they were between 1975 and 2000.
Other factors the researchers blamed were changes in rainfall, with reductions tending to reduce ice cover, and the burning of fossil fuels, which lead to soot that lands on snowy glacier surfaces, absorbing sunlight and hastening melting.
“It shows how endangered [the Himalayas] are if climate change continues at the same pace in the coming decades,” said Etienne Berthier, a glaciologist at France’s Laboratory for Studies in Geophysics and Spatial Oceanography, who was not involved in the study.
A separate study also published on Wednesday found that Greenland’s ice sheet might have completely melted within the next millennium if greenhouse gas emissions continue at their current rate.
The Greenland ice sheet holds the equivalent of 7m of sea level.
“If we continue as usual, Greenland will melt,” said lead author Andy Aschwanden, a research associate professor at the University of Alaska Fairbanks’ Geophysical Institute.
It is the most recent warning about warming in the world’s coldest regions.
“What we are doing right now in terms of emissions, in the very near future, will have a big long-term impact on the Greenland ice sheet and by extension, if it melts, to sea level and human society,” Aschwanden said.
The study, which used data from NASA’s Operation IceBridge airborne campaign and was published in Science Advances, is the latest to suggest a much greater rate of melt than was estimated by models.
The model relies on more accurate representations of the flow of “outlet glaciers,” river-like bodies of ice that connect to the ocean.
“Outlet glaciers play a key role in how ice sheets melt, but previous models lacked the data to adequately represent their complex flow patterns,” NASA said in a statement about the study. “The study found that melting outlet glaciers could account for up to 40 percent of the ice mass lost from Greenland in the next 200 years.”
As ocean waters have warmed over the past two decades, they have melted the floating ice that once shielded the outlet glaciers.
As a result, “the outlet glaciers flow faster, melt and get thinner, with the lowering surface of the ice sheet exposing new ice to warm air and melting as well,” it said.
In the next 200 years, the ice sheet model shows that melting at the present rate could contribute 48cm to 160cm to sea level rise.
Republican US lawmakers on Friday criticized US President Joe Biden’s administration after sanctioned Chinese telecoms equipment giant Huawei unveiled a laptop this week powered by an Intel artificial intelligence (AI) chip. The US placed Huawei on a trade restriction list in 2019 for contravening Iran sanctions, part of a broader effort to hobble Beijing’s technological advances. Placement on the list means the company’s suppliers have to seek a special, difficult-to-obtain license before shipping to it. One such license, issued by then-US president Donald Trump’s administration, has allowed Intel to ship central processors to Huawei for use in laptops since 2020. China hardliners
Conjoined twins Lori and George Schappell, who pursued separate careers, interests and relationships during lives that defied medical expectations, died this month in Pennsylvania, funeral home officials said. They were 62. The twins, listed by Guinness World Records as the oldest living conjoined twins, died on April 7 at the Hospital of the University of Pennsylvania, obituaries posted by Leibensperger Funeral Homes of Hamburg said. The cause of death was not detailed. “When we were born, the doctors didn’t think we’d make 30, but we proved them wrong,” Lori said in an interview when they turned 50, the Philadelphia Inquirer reported. The
RAMPAGE: A Palestinian man was left dead after dozens of Israeli settlers searching for a missing 14-year-old boy stormed a village in the Israeli-occupied West Bank US President Joe Biden on Friday said he expected Iran to attack Israel “sooner, rather than later” and warned Tehran not to proceed. Asked by reporters about his message to Iran, Biden simply said: “Don’t,” underscoring Washington’s commitment to defend Israel. “We are devoted to the defense of Israel. We will support Israel. We will help defend Israel and Iran will not succeed,” he said. Biden said he would not divulge secure information, but said his expectation was that an attack could come “sooner, rather than later.” Israel braced on Friday for an attack by Iran or its proxies as warnings grew of
A prominent Christian leader has allegedly been stabbed at the altar during a Mass yesterday in southwest Sydney. Bishop Mar Mari Emmanuel was saying Mass at Christ The Good Shepherd Church in Wakeley just after 7pm when a man approached him at the altar and allegedly stabbed toward his head multiple times. A live stream of the Mass shows the congregation swarm forward toward Emmanuel before it was cut off. The church leader gained prominence during the COVID-19 pandemic, amassing a large online following, Officers attached to Fairfield City police area command attended a location on Welcome Street, Wakeley following reports a number