15 Million Face Threat of Sudden Glacial Lake Outburst Floods (GLOFs)

Nature Communications, 7 February 2023

Fifteen million people around the world are at risk from flooding caused by glacial lakes, with more than half of these people living in just four countries: Pakistan, China, India, and Peru. This study provides the first global assessment of the most vulnerable regions to glacial lake outburst floods (GLOFs); factoring in not just physical lake conditions, but also the proximity of downstream communities and their capacity to efficiently cope with flooding. GLOFs occur when streams of meltwater pool into large lakes at the base of rapidly melting glaciers. These lakes are growing in many regions, and can burst with little advanced warning, with floods that damage property, infrastructure, and agriculture as much as 120 kilometers downstream. A single flooding event can lead to thousands of lives lost. Authors determined that communities living in High Mountain Asia are the most vulnerable to GLOFs, with 9.3 million people at risk. They ranked Pakistan and China as the two countries with populations most in danger: Pakistan has 2.1 million people living near glacial lakes at risk of overflowing, and China has some of the largest and most numerous glacial lakes, which places it at high risk of extensive infrastructure damage. Glacial lakes across the world have, over the past three decades of rapid global warming, become increasingly dangerous and unstable. Understanding which areas face the greatest danger from glacial flooding will allow for more targeted and effective risk management actions, which help minimize loss of life and protect communities downstream.

https://www.nature.com/articles/s41467-023-36033-x