As glaciers melt and release massive amounts of water into surrounding lakes, 15 million people worldwide are at risk of deadly flooding, according to a new study.
More than half of people living in the shadow of a so-called glacial lake outburst flood disaster are in just four countries: India, Pakistan, Peru and China, according to a study in Tuesday’s issue of the journal Nature Communications. Another study, which is under review before publication, lists more than 150 such disasters in history and in the recent past.
North Americans and Europeans often don’t think about this threat, the study estimates, but one million people live just 10 kilometers (6 miles) from potentially unstable glacier-fed lakes.
One of the most devastating floods occurred in Peru in 1941, killing 1,800 to 6,000 people. In 2020, the outburst of a glacial lake in the Canadian province of British Columbia triggered a 330-foot (100 m) tsunami, although it caused no casualties. The 2017 floods in Nepal caused by a landslide were filmed by German climbers. Since 2011, Mendenhall Glacier in Alaska has caused small annual floods in what the National Weather Service calls a “suicide basin,” according to study lead author Caroline Taylor, a researcher at Newcastle University in the UK.
In 2013, heavy rains and floods caused by the bursting of a glacial lake killed thousands of people in India.
So far, climate change doesn’t seem to be causing more frequent floods, but as warming shrinks glaciers, lakes increase in volume and make them more dangerous when they give way to levees, according to scientists. Are being given.
“In the past we’ve seen glacial lake burst floods that have killed thousands of people in a single catastrophic event,” said study co-author Tom Robinson, a disaster risk scholar at New Zealand’s University of Canterbury. “And with climate change, glaciers are melting and lakes are getting bigger, making them potentially more unstable.”
Dan Sugar, a geologist at the University of Calgary who was not involved in the study, said the danger largely depends on the number of people living in the flood zone.
“In a warming world, we certainly envision larger glacial lakes,” Sugar said in an email. “But the risk of these lakes depends crucially on where people live and what their vulnerabilities will be.”
