
Surprising research finds Himalayan glaciers might be slowing down the effects of climate change
By Tom Howarth
We often think of climate change as a monodirectional process; humans emit greenhouse gases, causing our planet’s temperature to rise, with the natural environment usually considered a passive player in the whole ordeal. But what if it wasn’t that simple?
A recent paper in the journal Nature Geoscience has shown how glaciers in the Himalayas are responding to a warming mountain environment, all by themselves.
‘Glaciers are not just passive actors of climate change,’ said Nicola Colombo, co-author of the study published in December, ‘but they are able, in turn, to modify the local climate’.
In general, mountainous ecosystems are considered highly sensitive to climate change and are being affected at faster rates than other regions. The Tibetan Plateau, for example, has seen temperatures climb an average of 0.50–0.67°C per decade since the 1980s, compared to a global average of 0.19°C.
But when a team of researchers began to examine data from the Pyramid Observatory — a research station 5,035 metres above sea level on the southern slopes of Mount Everest that has been examining conditions hourly for the past 30 years — they noticed something unexpected. Instead of temperatures increasing, the average temperature has remained remarkably stable, and the maximum daily, or diurnal, temperature at the observatory has actually fallen.
A reanalysis of data from other glacial environments in the Himalayas and comparisons with regional climatic models showed a similar pattern was being exhibited elsewhere.
So, what could be driving this change?
How glaciers are fighting back against climate change
According to the study, as daytime temperatures in the world’s tallest mountain range have climbed due to global warming, the temperature difference between the cold surface of glaciers and the air has increased with it. ‘This leads to an increase in turbulent heat exchange at the glacier’s surface and stronger cooling of the surface air mass,’ explained Francesca Pellicciotti, a professor at the Institute of Science and Technology Austria (ISTA) and another of the paper’s authors.
As the surface air gets cooler, it also gets denser and sinks. This has the effect of drawing colder winds from higher altitudes down the slope, thus producing the local cooling effect that the team observed.
This phenomenon, the team believes, allows some glaciers to ‘fight back’ against global warming as the cooling thwarts melting.
However, it’s not all good news for Himalayan glaciers. The pumping of cool air down the mountains also produces another effect: it pushes precipitation further downhill. While some glaciers are benefiting from remaining cool, others may experience a more rapid loss of mass as they no longer receive snowfall from higher altitudes.

Impact on South Asia’s great rivers – the Ganges-Brahmaputra, Indus and Mekon
The vast ice and snow reservoirs in the Himalayan glaciers play a vital role in supplying essential water to billions of people in South Asia. Great rivers such as the Ganges-Brahmaputra, Indus and Mekong rely, in part, on these glaciers as sources.
‘In the Himalayas, the response of glaciers to climate change can directly affect the safe access to water for millions of people as well as increase the hydrogeological risk, such as the glacial lake outburst floods,’ said Nicolas Guyennon, a collaborator in the research.
Understanding where glaciers may remain stable for longer and where we can expect increased melting is, therefore, imperative, not just to preserve the pristine Himalayan environment but also to protect the lives of many of the world’s inhabitants.
Ultimately, the research shows that the cooling effect exhibited at these glacial sites and any slowing of melting that results are a reaction to our warming planet rather than a signal of long-term stability.
Looking ahead, the team is seeking to establish which conditions favour cooling and how long such effects might last. ‘Even if the glaciers can’t preserve themselves forever, they might still preserve the environment around them for some time,’ said Pellicciotti. ‘Thus, we call for more multidisciplinary research approaches to converge efforts toward explaining the effects of global warming.’
‘Considering glaciers as active actors [in] climate change occurring at high elevations is fundamental because we can better understand the impact on water and ecological resources of the periglacial environment,’ concluded Franco Salerno, lead author of the research. ‘Moreover, we will be able in the future to increase our ability to model the response of glaciers to global warming.’