Glaciers at risk

The Global Glacier Decline

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 sheets 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.

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.


Regions At Risk

• Ecuador, Peru and Bolivia - shrinking glaciers supply water year-round, and are often the sole source of water for major cities during dry seasons.
  
  
• The Himalayas - the danger of catastrophic flooding is severe, and glacier-fed rivers supply water to one third of the world's population.
  
  
• Small island nations such as Tuvalu and some of the Solomon Islands - sea level rise is submerging low-lying land and saltwater is inundating vital groundwater reserves.

Nature At Risk

• Royal Bengal tiger - endangered tigers that will lose a large portion of their worldwide habitat as the Sundarbans succumb to sea level rise.
  
  
• Kittlitz’s murrelet - rare birds specialized to hunt in cloudy glacier water and nest on top of ice.
  
  
• Coral reefs - unique organisms that can be starved of energy from the sun when sea levels rise.

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 recorded in previous years.
  
  
• The northern Andes contain the largest concentration of glaciers in the tropics, but these glaciers are receding rapidly and losses have accelerated during the 1990s.
  
  
• Glacier melting has accelerated in the European Alps. 10-20% of glacier ice in the Alps has disappeared in less than two decades.

Read on: Glacier Facts