Mountains in a changing climate

Posted: 13 May 2008

Climate change will have significant impacts on both mountain people and billions living downstream from, and travelling through, mountain areas.

Increasing temperatures are only one of the factors to consider; and in some cases may have a positive impact, for instance through shortening winter seasons and thus reducing energy needs. However, higher temperatures may also mean that rain falls instead of snow, greatly affecting the timing of water flows - as well as the ski industry.

For many years, Europeans did not believe there could be snow on a mountain so close to the equator. Today, Kilimanjaro's icy peak attracts more than 20,000 visitors a year but now its ice cap is melting.© Rick Thomson/Thomson Safaris

Perhaps the greatest, and most unpredictable, risks will come from more frequent extreme events, such as floods, avalanches, landslides, and hurricanes.

  • Mount Kilimanjaro has lost 82 per cent of its icecap since 1912. Both the European Alps and the Caucasus Mountains have lost half their ice in the past century. New Zealand glaciers have shrunk 26 per cent since 1890. In the thousands of glaciers in the Tien Shan Mountain Range bordering China and Russia, 22 per cent of the ice volume has disappeared in the past 40 years.

  • On 30 summits in the European Alps, the number of plant species has increased in recent decades. The upwards movement for the eight most common species is 4 metres per decade.

  • In the Scottish Highlands, since the late 1970s, the number of days with snow lying has decreased at a rate of 12 days per decade. Especially for lower-elevation resorts, the region's skiing industry is increasingly at risk.

  • In the East African Highlands, precipitation and temperature have been rising since the 1990s. This appears to be related to increased epidemics of malaria at higher altitudes in Kenya, Ethiopia, and Tanzania. Similar epidemics have been reported in Burundi, Madagascar, and Rwanda.

  • Peru's Qori Kalis glacier retreated 13 feet each year between 1963 and 1978. By 1995, the annual rate of retreat was 99 feet. In the short run, the melting will cause hydroelectric dams and reservoirs to be flush with water, but in the long run, the sources will run dry and communities may use oil or coal for power instead, adding more greenhouse gases to the environment.

  • Australia's alpine ecosystems could disappear in 70 years. Sub-alpine trees in the Snowy Mountains have started growing 40 metres higher in the past 25 years as a result of global warming. Only 100 metres separate the tree-line from the top of some mountains. Yet there are more than 250 species of alpine plants growing in the shrinking habitat.

  • It is likely that the variability of precipitation of the Asian summer monsoon will increase, greatly influencing the lives of the hundreds of millions of people living in the region's mountains and downstream.

  • South Africa's Cape Floral Kingdom, exceptionally rich in endemic species, could be wiped out as a result of temperature changes expected this century. Other species under threat from climate change are the mountain gorilla in Africa, the spectacled bear of the Andes, and the resplendent quetzal in Central America.
Key source:

McCarthy, J.J., et al. (eds.) (2001) Climate Change 2001: Impacts, Adaptation, and Vulnerability: Contribution of Working Group II to the Third Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press.

Compiled by Dr Martin Price, Director of the Centre for Mountain Studies at Perth College, within Scotland's UHI Millennium Institute, 'creating the University of the Highlands and Islands'.