Glaciers in the Himalayas are melting rapidly, but a new report showed an astonishing phenomenon in the world’s tallest mountain range could be helping to slow the effects of the global climate crisis.
When warming temperatures hit certain high-altitude ice masses, it sets off a surprising reaction that blows robust cold winds down the slopes, according to the study published December 4 in the journal Nature Geoscience.
The warming climate creates a greater temperature gap between the surrounding air above Himalayan glaciers and the cooler air directly in contact with the ice masses’ surface, explained Francesca Pellicciotti, professor of glaciology at the Institute of Science and Technology Austria and lead author of the study.
“This leads to an increase in turbulent heat exchange at the glacier’s surface and stronger cooling of the surface air mass,” she said in a news release.
As the cool, dry surface air gets cooler and denser, it sinks. The air mass flows down the slopes into the valleys, causing a cooling effect in the glaciers’ lower areas and neighboring ecosystems.
With ice and snow from the mountain range feeding into 12 rivers that provide fresh water to nearly 2 billion people in 16 countries, it’s important to find out whether the Himalayan glaciers can keep up this self-preserving cooling effect as the region faces a likely rise in temperatures over the next few decades.
Glacier melt
A June report previously covered by CNN showed that glaciers in the Himalayas melted 65% faster in the 2010s compared with the previous decade, which suggests rising temperatures are already having an impact in the area.
“The main impact of rising temperature on glaciers is an increase of ice losses, due to melt increase,” said Fanny Brun, a research scientist at the Institut des Géosciences de l’Environnement in Grenoble, France. She was not involved in the study.
“The primary mechanisms are the lengthening and intensification of the melt season. They cause glaciers to thin and retreat, leading to deglaciated landscapes that tend to further increase the air temperature due (to) larger energy absorption by the surface,” Brun said.
That energy absorption at the surface is determined by something called the albedo effect. Light or “white” surfaces such as clean snow and ice will reflect more sunlight (high albedo) compared with “dark” surfaces such as the land that is exposed as glaciers retreat, soil and oceans (low albedo). In general, Brun said this phenomenon is interpreted as a positive feedback loop, or a process that enhances a change, but it is overall poorly studied and difficult to quantify.
This is an abridged version of the report produced by CNN.
