Glaciers at risk

Pasterze Glacier lies in the Hohe Tauern mountain range of the Alps, along the northeastern slope ... rel=
Pasterze Glacier lies in the Hohe Tauern mountain range of the Alps, along the northeastern slope of Austria tallest mountain, Grossglockner, and flows into the Moell River. The 9 kilometre-long Pasterze is currently losing 5 metres in height and 20 metres in length every year.The retreat of Pasterze is monitored by satellite and is used in many models to estimate the loss of mountain glaciers around the world.
© WWF-Canon / Michèle DÉPRAZ

The watersheds of the world are shrinking

Glaciers are ancient rivers of compressed snow that creep through the landscape, shaping the planet's surface. They are the Earth's largest freshwater reservoir, collectively covering an area the size of South America.

Glaciers have been retreating worldwide since the end of the Little Ice Age (around 1850), but in recent decades glaciers have begun melting at rates that cannot be explained by historical trends. Projected climate change over the next century will further increase the rate at which glaciers melt. Average global temperatures are expected to rise between 1.4 and 5.8°C by the end of the 21st century.

Simulations project that a 4°C rise in temperature would cause nearly all of the world's glaciers to melt.

For example, the meltdown of the Greenland ice sheet could be triggered at a temperature increase of 2-3°C. Even in the least damaging scenario, say a 1°C rise along with an increase in rain and snow, glaciers will continue to lose volume over the coming century.

The importance of glaciers for human populations and ecosystems


Although only a small fraction of the planet's permanent ice is stored outside of Greenland and Antarctica, these glaciers are extremely important because they are particularly susceptible to climate change and their loss directly affects human populations and ecosystems.

Continued and widespread melting of glaciers during this century will lead to floods and water shortages for millions of people. As sea levels rise, coastal communities and habitats will be destroyed.

Fast facts - Glacier retreat in all continents

  • Nearly all glaciers surveyed in Alaska are melting. Thinning rates in the last 5 to 7 years are more than twice those seen in previous years. Half of the water flowing into the oceans, globally, due to melting glaciers, is a result of melting in Alaska.
  • The northern Andes contain the largest concentration of glaciers in the tropics, but these glaciers are receding rapidly and losses accelerated during the 1990s.
  • Glacier melting has accelerated in the European Alps since 1980, and 10 to 20% of glacier ice in the Alps was lost in less than two decades. Half the volume of Europe's Alpine glaciers has disappeared since 1850. By the end of this century, half of those left will have gone as well.
  • Tropical glaciers in Africa have decreased in area by 60% to 70% on average since the early 1900s.
  • The vast majority of all Himalayan glaciers have been retreating and thinning over the past 30 years, with accelerated losses over the last decade.
  • The tropical glaciers in the Pacific have retreated, although in New Zealand some glaciers grew due to increased precipitation.
  • Arctic glaciers have been receding, with the exception of Scandinavia and Iceland where increase in precipitation resulted in glacier growth. Greenland alone contains 12% of the world's ice; entire portions of the Greenland ice sheet appear to be sliding towards the sea.
  • In Antarctica the centre of the continent is currently cooling so it won't be melting soon. However, coastal glaciers and ice sheets in the Antarctic are melting. The melting of ice sheets and ice shelves that sit on top of land, will result in higher sea levels.

NB. These facts are from the WWF report GOING, GOING, GONE! Climate Change And Global Glacier Decline. References are available here [pdf, 122 KB].

Glaciers in the Himalayas

  • Alton Byers is a mountain geographer and WWF Climate Witness who has spent many years working in the Himalayas. In this short audio presentation Alton talks about the impact of climate change on glaciers in the Mt. Everest area.

    Watch presentation now

Subscribe to our mailing list

* indicates required