Explained: 50 lakh people in India, Pakistan at risk of flooding from glacial lakes due to climate crisis

Glacial lakes are formed by the meltwater from shrinking glaciers. These glacial lakes tend to suddenly burst and deposit large amounts of water in the downstream areas.

This is known as glacial lake outburst floods or GLOF, which have been taking place since the ice age. However, the risk of such floods has increased multifold in recent times due to climate change, as the glaciers are retreating at a faster rate.

GLOFs can be highly destructive as they can spread over a large distance from the original site. In some cases, they can spread more than 120 km.

The study states since 1990, the number and size of glacial lakes have grown rapidly along with the downstream population.

Thus, GLOFs can be catastrophic as they arrive with little warning and result in large-scale destruction of property, infrastructure, agricultural land and life.

The study estimates that 15 million (1.5 crores) people live within the 50 km danger zone of glacial lakes.

Populations in High Mountains Asia (HMA), a region stretching from the Hindu Kush all the way to the eastern Himalayas are the most exposed.

As per the study, on average around one million people live within 10 km of a glacial lake in the region.

“India and Pakistan make up one-third of the total number of people globally exposed to GLOFs — around three million people in India and around two million people in Pakistan,” Tom Robinson, the co-author of the paper told the Indian Express.

The study also found that the risk of damage from glacial flood doesn’t just depend on the size and number of glacial lakes in an area but the number of people living in the area, their proximity to the danger zone and the levels of social vulnerability.

“While the number and size of glacial lakes in these areas (India and Pakistan) isn’t as large as in places like the Pacific Northwest or Tibet, it’s that extremely large population and the fact that they are highly vulnerable that means Pakistan and India have some of the highest GLOF danger globally. In fact, the most dangerous catchment in the world in our study is Khyber Pakhtunkhwa in Pakistan,” Robinson explained in the report.

However, the most surprising finding by the scientists was Peru, which is ranked third in the global danger levels.

The study adds that in the past two decades, glacial lakes across the Andes have increased by 93 percent, in comparison to 37 percent in high-mountain Asia amid the worsening climate crisis.

According to Robinson, no single solution would work in reducing the risk of GLOFs as it is very complex.

He explained that there is a need to find effective measures by working with national and regional governments, as well as communities to find appropriate measures for the threatened populations.