A new study of glaciers in the Himalayas has found that they are incredibly vulnerable to rising global temperatures, with concerning implications for some of Asia’s largest and most economically critical river systems.
Researchers from the International Centre for Integrated Mountain Development found that the so-called “Third Pole” could lose one-third of its glaciers, even if global warming is kept within the Paris Agreement’s lower threshold of 1.5C above pre-industrial levels. That would have huge knock-on impacts for Asian economies—250 million people live in the immediate region, and 1.65 billion people live in the valleys of the Ganges, Indus, Yellow, Mekong and Irrawaddy Rivers which are fed by these glaciers.
“This is the climate crisis you haven’t heard of,” Philippus Wester, one of the study’s authors, said. “Global warming is on track to transform the frigid, glacier-covered mountain peaks of the [Hindu Kush-Himalayas] cutting across eight countries to bare rocks in a little less than a century. Impacts on people in the region, already one of the world’s most fragile and hazard-prone mountain regions, will range from worsened air pollution to an increase in extreme weather events.”
The report from the ICIMOD adds to growing fears over the impacts of glacial ice melting on global weather.
In late January, analysis of satellite data showed a newly-discovered 9.5km long cavity under the Thwaites Glacier in West Antarctica, representing billions of tonnes of melted ice. The void has mostly been created over the past three years, researchers said.
The Thwaites Glacier is on an ice shelf the size of Florida, and has been retreating at a rate of 200m per year. Meltwater from the glacier is believed to be responsible for around 4 per cent of global sea level rise to date, and if it should collapse—something that scientists believe could be possible within the next 50 to 100 years at current rates—it could drive a further 60cm rise, which would threaten major coastal cities around the world.
Last week researchers led by Nick Golledge at the Victoria University of Wellington found that the combined melting of ice sheets at both poles could create a feedback loop that would hasten sea level rises, and could lead to an increase in the incidence of extreme weather events.
“Increasing meltwater from Greenland will lead to substantial slowing of the Atlantic overturning circulation, and that meltwater from Antarctica will trap warm water below the sea surface, creating a positive feedback that increases Antarctic ice loss,” the researchers said. “In our simulations, future ice-sheet melt enhances global temperature variability and contributes up to 25 centimetres to sea level by 2100.”