It is relatively common knowledge these days that the world’s glaciers are melting. The evidence has been visible for over one hundred and fifty years, with ice flows and glaciers retreating since the mid-nineteenth century; and three centuries before, this formed a period known as the Little Ice Age - the world’s temperatures dropped to levels that facilitated ice growth. But rising temperatures from 1850 onwards marked the end of the Little Ice Age, catalyzing a marked change in polar and alpine environments worldwide.
New evidence has shown that global glacier melting occurs at a higher rate than previously thought. A study published in the journal Nature assessed the behavior of nearly every known glacier in the world (about 217,000 or so)1. This makes it the most extensive such study ever undertaken, providing a comprehensive insight into the fortunes of these unique ice environments.
The findings are stark. Between 2000 and 2019, the world’s glaciers lost 267 gigatonnes of ice every year. It can be hard to get your head around a figure like that, so the study seeks to use an analogy to signify better just how substantial this degree of melting is. According to the researchers, the water loss from this amount of glacier melt would be enough to submerge Switzerland in six meters of water every year completely.
Even more concerning than this is the fact that the rate of ice melt is increasing. With each passing decade, the total ice loss in glaciers increases by about 48 gigatonnes per year. Some of the worst affected areas are Alaska, the Alps, and the Himalayas, where glaciers are overwhelmingly becoming thinner and less massive.
“The situation in the Himalayas is particularly worrying,” says Romain Hugonnet, lead author of the study and researcher at the University of Toulouse. “If Himalayan glacier shrinkage keeps accelerating, populous countries like India and Bangladesh could face water shortages in a few decades.”
It’s not just humans that will suffer from glacier retreat either. In frigid, high-altitude regions of the Himalayas, one species that rely on glacier habitats is the snow leopard. Known as the ‘ghost cat,’ the species is already classed as vulnerable by the IUCN, with less than 10,000 individuals left in the wild due to its secretive nature.
Snow leopards primarily inhabit mountainous regions of Asia, with the largest populations residing in China and Mongolia. This places the species in a very fragile part of the world, with the mountain ranges of central Asia and the Tibetan Plateau warming at twice the rate of the average seen in the Northern Hemisphere.
Snow leopards have been around for about 7 million years, surviving fluctuations in temperature and glacier ice loss in the past. However, the rate of warming during recent decades dramatically exceeds the ability of the species to adapt. With the news that glaciers are receding faster than previously thought, there is undoubtedly concern amongst conservationists.
As their icy habitats are lost, snow leopards will struggle to find food at high altitudes and will be forced further downslope, putting them in competition with humans, as well as other large predators. For example, large parts of the snow leopard’s range overlap with that of the common leopard, although this species lives at lower elevations. Both species are similar in size and have very similar feeding habits, meaning their existence in the same space leads to competition for resources.2
However, the snow leopard’s increased interaction with humans maybe even more detrimental. As they roam closer to human settlements, they are at greater risk of being hunted by poachers, with several hundred animals already being killed every year, mainly for their fur. Snow leopards are also more likely to kill livestock when forced downhill to find food, leading to conflict with local people. Not only is this a problem for the communities themselves, but it also means snow leopards are often killed in retribution.
Although it isn’t known for sure how snow leopard populations will react in the coming decades, the outlook is certainly worrying for this majestic species. With news that the rate of glacier retreat is speeding up, rather than slowing down, the impacts for alpine wildlife – as well as the health of global ecosystems as a whole – are likely to be severe.
Hugonnet, R., McNabb, R., Berthier, E., Menounos, B., Nuth, C., Girod, L., Farinotti, D., Huss, M., Dussaillant, I., Brun, F. and Kääb, A., 2021. Accelerated global glacier mass loss in the early twenty-first century. Nature, 592(7856), pp.726-731. ↩
Li, J., McCarthy, T.M., Wang, H., Weckworth, B.V., Schaller, G.B., Mishra, C., Lu, Z. and Beissinger, S.R., 2016. Climate refugia of snow leopards in High Asia. Biological Conservation, 203, pp.188-196. ↩