Climate change will melt vast parts of the Himalayas, study says

The report highlights previous studies that predicted glacier volumes in this region could decline between 45% and 90% through the 21st century.

Climate change is a serious threat to the 240 million people who live across eight countries in the Hindu Kush Himalaya and the 3 billion others who rely on food produced in the area, the assessment says.

"The consequences are pretty extreme. We are concerned, and we are worried," said one of the report's authors, Philippus Wester, chief scientist with the International Centre for Integrated Mountain Development. "Urgent climate action is needed."

Glaciers have been retreating and thinning in the area since the 1970s, the report says, but there's been an accelerating rate of retreat since then. This loss has caused severe economic damage and floods, landslides and deadly epidemics. Global warming has also reduced snow cover and degraded permafrost.

The consequences of inaction will be devastating, the assessment says.

Climate change will reduce how much food farmers will be able to produce in this part of the world. About 70% of the population of this region are farmers, and there is already great food insecurity there.

Warmer water temperatures will encourage the growth of invasive species. Extreme floods and droughts may "destroy the food production base of the region," the report said. Rivers that farmers and energy companies rely on, like the Ganges, Yangtze, Mekong and Indus, will also be hurt by glacier melt.

Ultimately, climate change will probably increase the risk of violent conflict and add to the political instability.

And it's not just this region that will be affected. An ice melt could push sea levels higher around the world.

The Hindu Kush Himalayan Assessment was put together by more than 200 authors aiming to create a baseline of knowledge to understand the region that includes China, India, Myanmar, Nepal, Afghanistan, Pakistan, Bangladesh and Bhutan.

The report says that "in spite of its importance, relatively less is known" about the region and its ecosystems. The authors hope it will be used to encourage cross-border cooperation among the regions leaders to find ways to prevent the potential devastation that climate change can bring.

"This is a wake-up call," Wester said. "Can we come together as humanity and rise to the occasion? I think we can. Yes, a lot of people want to be in denial. Yes, this is a story we don't want to hear because of our day-to-day issues, but the technology is there, and we have ways of reducing greenhouse gas. I'm an optimist, but time is running out, and we need to address this now, not next year or later. We need to have this conversation now. Otherwise, we are in trouble."