Fifteen million people are at risk from melting glaciers.
Scientists have compiled the first global assessment of the threat posed by glacial lake outburst floods, estimating that approximately 15 million people worldwide live in the potentially hazardous zone. The study was published in the journal Nature Communications.
Glacieral lakes form when meltwater from glaciers melting due to global warming accumulates behind natural dams of ice and debris.
Such dams are unstable: if they fail, a huge volume of water, ice, and rock suddenly rushes down the valley.
This phenomenon, known as a glacial lake outburst flood (GLOF), can destroy settlements, bridges, and roads located tens of kilometers downstream in minutes.
Researchers from Northumbria University, led by Caroline Taylor, estimated how many people live within a 50-kilometer flood zone around glacial lakes worldwide.
Approximately 15 million people are within this zone, with approximately 300,000 of them living dangerously close—less than 5 kilometers from such bodies of water.
The most vulnerable areas are the mountainous regions encompassing the Himalayas and neighboring ranges.
These regions account for the majority of the population living at risk; the top three countries at risk are China, Pakistan, and India, with Peru having the third-highest number of people at risk.
Combined, India, Pakistan, Peru, and China account for more than half of all those threatened by such floods.
The authors emphasize that the main risk factor is not the size of the lake itself, but the population density and vulnerability of people downstream.
The Andes are particularly alarming: the number of glacial lakes there has increased by 93% since 1990, compared to 37% in High Asia. However, this region is poorly studied—less than a hundred scientific papers have been devoted to it since the late 1970s.
Scientists are calling for more attention and resources to be directed specifically to developing mountain regions, where the combination of rapidly growing lakes, poverty, and a growing population poses the greatest threat.
Scientists previously reported that climate change in Antarctica is rapidly changing. The fate of the peninsula itself could be decided within the next 10 years.
