Climate change leading to water shortage in Himalayas: Study

Climate change is driving glaciers in the Himalayas to melt more rapidly than at any point in the last 10,000 years, and could soon cause water supply shortage in parts of India, Pakistan, and Nepal, a study has warned.

Researchers from Ohio State University in the US showed that climate change could have devastating effects on vulnerable residents in the Andes mountains and the Tibetan plateau.

"By 2100, the best case scenario is that half of the ice will disappear. Worst-case scenario: two-thirds of it will. And you've got all those people depending on the glacier for water," said Lonnie Thompson, a climate scientist at Ohio State University.

Researchers showed that while water supply is declining, demand is rising because of growing populations.

The glaciers in Peru supply critically needed water for people, crops and livestock.

In 2016, researchers in China and India launched a research initiative to conduct similar research on the Tibetan plateau, which holds thousands of glaciers that supply water to people in parts of Afghanistan, Bhutan, China, India, Nepal, Pakistan and Tajikistan.

The international research team dubbed the plateau the "Third Pole" because it contains the largest stores of freshwater in the world outside of the North and South poles.

Since then, they have drilled ice core samples from across the Tibetan plateau and the Andes mountains, examining the ice for clues about temperature, air quality and other large-scale events in history.

"The last 200 years or so, we really understand. Now we are looking at the last 10,000 years," said Thompson.

There have been times throughout history when the glacial ice cores showed temperatures increased -- during an El Nino, for example.

However, within the last century, the cores from both the Andes and the Himalayas show widespread and consistent warming.

"This current warming is not typical," Thompson said.

"It is happening faster, it is more persistent and it is affecting glaciers in both Peru and India. And that is a problem, because a lot of people rely on those glaciers for their water," he said.

Melting glaciers can trigger such hazards as avalanches and floods. They also can have long-lasting effects on a region's water supply.

As the glaciers melt, initially those regions will have more water. However, over time, as the glaciers shrink, the water those glaciers typically supply will dwindle, Thompson said.

"Precipitation is down and temperatures are up and that leads to retreating glaciers," he added.

"There are 202 million people in Pakistan who rely on water from the Indus River -- and that river is fed by the glacier," Thompson said.

The effects in Peru, too, could be far-reaching, particularly on Peruvian agriculture and on the water supply in Lima, the Peruvian capital.

Researchers are hoping that by studying the glaciers in both areas, they will find answers to slow glacial retreat -- or to provide new water sources to at-risk areas.