For the first time, scientists have determined the volume of freshwater stored in various glacial lakes around the world, reflecting the sheer volumes of ice that has melted for years and became liquid in response to climate change.
Scientists analyzed over 250,000 satellite images of glacial lakes around the world between 1990 and 2018, and found around 48%, to 156.5km3, according to the research published in the journal Nature Climate Change.
In other metrics, the volume of glacial lakes increased by 53% between 1990 and 2018; taking the total land area covered by lakes to 51%.
Major glacial lakes are formed when significant ice melts and collect in natural gorges formed in the mountains. These lakes keep expanding as the ice melts, but the rate at which these lakes grow has been as if fast-forwarded in the wake of climate change.
According to the 10 scientists who have contributed to the paper titled ‘Rapid worldwide growth of glacial lakes since 1990’ the role of glacial lakes as a terrestrial source of freshwater is yet to be known. Nor is it clear the relation between these gazillion liters of waters and rise in ocean level.
“Our findings show how quickly Earth surface systems are responding to climate change and the global nature of this,” Stephan Harrison, a professor of climate and environmental change at Exeter University told the Guardian.
“More importantly, our results help to fill a gap in science because, until now, it was not known how much water was held in the world’s glacial lakes.”
Most of the rise in the glacial waters took place in Scandinavia, Russia, and Iceland, where, there are now double the volume of areas covered in glacial lakes within the study period.
Between 1990-1999 timeframe, there were 9,414 glacial lakes, covering approximately 5.93 × 103 km2 of the Earth’s surface, holding 105.7 km3 of water.
The same count for the 2015-2018 figure showed 14,394 glacial lakes, which is a 53% increase over 1990–1999, the researchers noted.
Glacial lakes which are gigantic stores of freshwater are a source of life to many poor populations who inhabit areas near such lakes like in Asia and South America.
However, these water pools are also a threat to civilization on occasions the waters break the natural barriers and bust out downstream causing widespread destruction.
Scientists are particular worries about the bigger glacial lakes that pose a greater threat of outbursts. “These are a real hazard in many valleys connected to retreating glaciers in parts of the Himalayas and Andes, for example,” Stephan Harrison said.
Numerous hydroelectric power plants, cross-border pipelines, major roadways dot the mountainous regions where retreating glaciers are a threat.
Remembering the horrors – ‘Himalayan Tsunami’
Seven years back, the world woke up to one of the deadliest floods caused by glacier lakes. Unspeakably horrifying images surfaced on social media, showing the holy town of Kedarnath turned into a post-apocalyptic set.
For instance, the 2013 Kedarnath floods, dubbed the ‘Himalayan Tsunami’ was partly caused due to an outburst of a retreating glacier which fed a nearby lake at alarming volume, causing the natural dams to shatter.
Climate-induced changes altered the glacial stability in the region, while a perfectly-timed outpour fed to the cause of the outbreak of gazillion tones of water.
In a matter of a few hours, the deadly gush of ice, rocks, and waters blew out anything that came in the way. A least 7000 were dead, tens of thousands stranded on the holy pilgrimage site of Kedarnath where devotees flock to pay homage in an eighth-century temple.