Declines in snow and ice cover

Most of the global ice and snow cover is rapidly declining. This will have large global, regional and local consequences for human beings and nature. This is the main message of the UNEP report “Global Outlook for Ice and Snow” which was presented in Tromsø today.   

- The report gives a comprehensive presentation of the current changes in snow and ice cover at a global scale, and its consequences for human beings and ecosystems. I am specially concerned about how climate change turns out to be a reinforcing process. The melting of ice and snow from the increase in temperature will lead to further global warming. We have started an accelerating process, and we do not know its outcome, says the Norwegian Minister of Environment, Helen Bjørnøy.  

-  The challenge of global climate change can only be met through reinforced political action. Our main goal now should be to work for a breakthrough in the climate change negotiations at Bali in December, which could pave the ground for a global agreement on future emission reductions at the latest in Copenhagen in 2009, the minister says.

The land snow cover in the Northern Hemisphere in March and April has been reduced by 7-10 per cent over the last 30-40 years.  Most of the Alpine areas have also experienced significant reductions in snow cover. The season of the year with no snow cover has been extended over the whole Northern Hemisphere as well as in the Alpine areas. 

Over the last 30 years the extension of sea ice has been reduced by 6-7 per cent in the winter and 10-12 per cent in the summer season. The ice thickness has been reduced by at least 10-15 per cent.  

The Greenland ice sheet loses 150-200 km3 per year. The reduction rate has been doubled over the last 2-3 years. With the current melting rate it will, however, take 10-15 thousand years to make Greenland completely snow and ice free.  

Global warming will be reinforced by the reduction in snow and ice cover. The reflection of sun beams from the earth surface will be reduced and more of the sun heat absorbed by the land and polar oceans, increasing the warming effect. Another “positive feedback” from an increase in temperature is the release of stored greenhouse gases from the thawing of permafrost.  

The sea level is expected to rise with 20-80 cm in this century, but the contribution from glaciers is uncertain. A sea level rise of for instance 2 meters will have dramatic negative impacts on low-lying countries like Bangladesh and the Netherlands and Small Island States.  

- Reduced snow and ice cover at a global level give reasons for great concern. It will lead to reduced water access, flood increases and destruction of ecosystems.  And the poorest will face the worst consequences. Small Island Developing States and small coastal communities in the Arctic will be among the most vulnerable ones. And they are already experiencing the impacts of the changes. The culture and living conditions are threatened, and there is a great need to assist these countries and communities in adapting to the changes, the Norwegian Minister of International Development, Erik Solheim, says.  

It is estimated that 1,3-1,5 billion people are dependent on water from rivers influenced by the melting of snow and ice. 2-300 millions of these are expected to be critically dependent on snow and ice melting in periods with low precipitation. In Central-Asia, Peru and Chile large land areas totally rely on melting water from snow and glaciers. As much as 40 per cent of the world population is expected to be, directly or indirectly, affected by the impacts of reduced snow and mountain ice in Asia.