Pioneering Discovery Reveals a Remarkable Phenomenon in the Himalayas Counteracting Climate Change
Cold winds sweeping down the Himalayas have been discovered to play a surprising role in slowing glacier melting, according to a recent report This phenomenon offers valuable insights into the contrasting glacier loss patterns between Asia and Europe
The rapid melting of Himalayan glaciers has revealed a surprising phenomenon that may be helping to slow the effects of the global climate crisis. A new report published in the journal Nature Geoscience on December 4 found that when warming temperatures impact high-altitude ice masses, it triggers a reaction that sends strong cold winds down the slopes.
The warming climate causes a larger temperature difference between the air above the Himalayan glaciers and the cooler air touching the ice, as noted by Francesca Pellicciotti, a glaciology professor at the Institute of Science and Technology Austria and the study's lead author. "This results in heightened turbulent heat exchange at the glacier's surface and more intense cooling of the air above," she explained in a press release.
As the cool, dry surface air cools and becomes denser, it descends. This downward flow of air moves into the valleys, resulting in a cooling effect in the lower areas of the glaciers and nearby ecosystems.
The ice and snow from the mountain range feed into 12 rivers, supplying fresh water to nearly 2 billion people in 16 countries. It is crucial to determine if the Himalayan glaciers can maintain this self-preserving cooling effect as the region is expected to experience a rise in temperatures in the coming decades.
Schematic diagram of the air cooling in the surroundings of Himalayan glaciers as they react to global warming.
Salerno/Guyennon/Pellicciotti/Nature Geoscience
Glacier melt
CNN previously reported in June that the glaciers in the Himalayas melted 65% faster in the 2010s compared to the previous decade, indicating that increasing temperatures are already affecting the region.
Fanny Brun, a research scientist at the Institut des Géosciences de l'Environnement in Grenoble, France, who was not part of the study, stated, "The main impact of rising temperatures on glaciers is an increase in ice loss due to increased melting."
"Brun explained that the main contributing factors are the extension and increased intensity of the melting season. These factors result in the thinning and retreat of glaciers, which then leads to deglaciated terrains that have the tendency to further raise the air temperature by absorbing more energy from the surface,"
The image shows scientists engaged in a discussion about their findings during a field trip. From left to right: Nicolas Guyennon (IRSA-CNR), Francesca Pellicciotti (ISTA), and Thomas Shaw (ISTA).
Image credit: Franco Salerno/The Institute of Science and Technology Austria
The energy absorption at the surface is determined by the albedo effect. Surfaces with high albedo, such as clean snow and ice, reflect more sunlight compared to low albedo surfaces like exposed land, soil, and oceans. This is generally considered a positive feedback loop that enhances a change, but it is poorly studied and difficult to quantify.
However, at the base of Mount Everest, measurements showed that overall temperature averages remained stable rather than increasing. A detailed analysis of the data uncovered the true situation.
"Franco Salerno, a researcher for the National Research Council of Italy, noted that while minimum temperatures have been increasing, surface temperature maxima in summer have been consistently decreasing," said Salerno, who coauthored the report.
Despite the presence of cooling winds, the rising temperatures and glacier melt due to climate change are not fully countered. Thomas Shaw, a member of the ISTA research group with Pellicciotti, explained that the rapid melting of glaciers is a result of complex factors.
"The cooling is local, but perhaps still not sufficient to overcome the larger impact of climatic warming and fully preserve the glaciers," Shaw said. Â
Glaciologists climb over the collapsed tongue of the Findel Glacier (Valais). The radiantly blue glacial lakes were still covered by dozens of metres of ice a decade ago.
Matthias Huss/GLAMOS
Switzerland's glaciers have lost an astonishing amount of ice in just two years.
Pellicciotti pointed out that the study team focused on using the limited ground observation records at a station in the Himalayas due to the overall lack of data in high-elevation areas worldwide.
She noted that the process highlighted in the paper could potentially occur on any glacier worldwide given the right conditions.
The new study offers strong motivation to gather more high-elevation, long-term data that are crucial to substantiate the new findings and their broader impacts, according to Pellicciotti.
Data Goldmine
Situated at a glacier-covered height of 5,050 meters (16,568 feet), the Pyramid International Laboratory/Observatory climate station is positioned on the southern side of Mount Everest. For nearly three decades, the observatory has meticulously documented meteorological information.
Pellicciotti, Salerno, and their research team utilized detailed meteorological data to determine that rising temperatures are causing katabatic winds, cold winds that form as air descends in mountainous areas such as the Himalayas.
The Pyramid International Laboratory/Observatory climate station on Mount Everest has recorded hourly meteorological data for nearly three decades.
Franco Salerno, from The Institute of Science and Technology Austria, noted that katabatic winds are a regular occurrence in Himalayan glaciers and valleys. However, he also mentioned that there has been a noticeable increase in the strength and duration of these winds, which he attributed to rising air temperatures in a warming world.
The team also noted that lower temperatures were associated with higher ground-level ozone concentrations. This indicates that katabatic winds act as a pump, moving cold air from higher elevations and atmospheric layers down into the valley, as explained by Pellicciotti.
Brun added, "Based on current knowledge, Himalayan glaciers are experiencing slightly lower levels of mass loss compared to other glaciers."
Glacier loss in Asia vs. Europe
Brun explained that in Central Himalaya, on average, the glaciers have thinned about 9 meters (29.5 feet) over the past two decades.Â
"This is significantly less than the thinning of European glaciers, which have decreased by about 20 meters (65.6 feet) over the same period, but it is greater than other regions in Asia (such as the Karakoram region) or the Arctic region," Brun explained.
Understanding the duration for which these glaciers can locally mitigate the impacts of global warming could be essential in effectively addressing our changing world.
West Antarcticahome to the Thwaites Glacier, also known as the "Doomsday glacier"is the continent's largest contributor to global sea level rise.
Jeremy Harbeck/OIB/NASA
Rapid melting in West Antarctica is unavoidable, with potentially disastrous consequences for sea level rise, study finds
Study coauthor Nicolas Guyennon, a researcher at the National Research Council of Italy, stated, "We believe that the katabatic winds are the response of healthy glaciers to rising global temperatures and that this phenomenon could help preserve the permafrost and surrounding vegetation."
However, further analysis is required. The study team's next goal is to pinpoint the glacial characteristics that contribute to this cooling effect. Pellicciotti noted the absence of long-term ground stations for testing this hypothesis in other locations.
"Despite the inevitable decline of glaciers, there is still potential to preserve the surrounding environment for a temporary period," she emphasized. "Therefore, there is a need for increased multidisciplinary research efforts to unite in addressing the impacts of global warming."
In 2019, a distinct study revealed that even under the most optimistic scenario, limiting average global warming to just 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial levels, the Himalayan region would still experience a minimum loss of one-third of its glaciers.
