Global Outlook for Ice & Snow

Foreword

Ice, snow and climate change are closely linked. The Global Outlook for Ice and Snow investigates those con- nections, the current situation of ice and snow and the global significance of changes, now and in the years to come. The book was prepared for World Environment Day 2007 to provide an up-to-date assessment on this year’s theme: Melting Ice – A Hot Topic? The Global Out- look for Ice and Snow is the second thematic assessment report in UNEP’s Global Environment Outlook series. It was written by teams of experts from different disci- plines and many countries and has included leading re- search organizations in the preparation and the review- ing of the book. Ice and snow on land, in the seas, and in the ground, col- lectively known as the cryosphere, are defining compo- nents of ecosystems in the northern part of the Northern Hemisphere, in Antarctica and in the world’s mountain regions. Changes in ice and snow alter the distribution of Earth’s heat and water, and influence regional and global ocean circulation. Many plants and animals such as the polar bear have evolved to live on, in and around ice and cannot survive without it. Traditional cultures are intimately tied to ice and snow in the far North and inmountain areas. For many people in north- ern and mountain regions, ice and snow are part of daily winter life, a resource for recreation and income generation, and an important part of national and regional identity. In high mountain areas, particularly in the Himalayas and Andes, ice and snow are important sources of water for billions of downstreamusers; frequently maintaining

river flows and the recharge of aquifers in dry seasons. Glaciers are melting, sea ice is shrinking, permafrost is thawing. These changes have widespread impacts, from collapsing infrastructure in the Arctic to increased flood- ing of small islands in the South Pacific. Reports of the Intergovernmental Panel on Climate Change (IPCC), founded by UNEP and the WMO, re- flect our best understanding and knowledge on climate change, and identify uncertainties and research needs. March 1 of this year marked the start of International Polar Year (IPY) 2007–2008, the largest-ever internation- al polar research programme. Much IPY research is di- rected to answering questions and resolving uncertain- ties about the cryosphere and climate change. The IPCC’s 4th Assessment reports underline the far reaching implications of changes in ice and snow. For example a total loss of Himalayan glaciers could hap- pen within the lifetimes of many alive today affecting the water supplies of hundreds of millions of people. Climate change has indeed moved to the top of the glo- bal sustainable development agenda. The Global Outlook for Ice and Snow will serve as a reference publication in the debate, contribute to effective decision-making and ultimately the action so urgently needed.

Achim Steiner United Nations Under-Secretary-General and Executive Director, United Nations Environment Programme

GLOBAL OUTLOOK FOR ICE AND SNOW