Rapidly warming Arctic temperatures pose diverse, wide-ranging risks, says impact studyAverage temperatures in the Arctic have risen at almost twice the rate of that of the rest of the world over the past several decades, and greater changes are still to come, with consequences which will be serious and felt far beyond the Arctic region. This is one of the key findings of the Arctic Climate Impact Assessment (ACIA), a multidisciplinary, multinational study released last week. It represents the most detailed assessment to date of changes in circumpolar climate and ultraviolet radiation and their consequences for Arctic people and ecosystems.
While noting that the changing climate may give rise to new opportunities in the North, such as increased access to oil and gas minerals, the ACIA found that Aboriginal communities in the circumpolar Arctic will suffer serious economic and social impacts.
For example, the ACIA found the range and availability of species of polar bear, walrus, seals and caribou are already beginning to change. This fact, together with shifting ice and weather conditions, will pose major challenges to human health and food security for many communities.
"The assessment sends a message to all nations - climate change is real, it is happening now and it is a truly global challenge. No nation and no region is immune to its impacts," said federal Environment Minister StÈphane Dion. "The Arctic is bearing witness now to the kind of changes other regions will soon see. This is a wake- up call for all of us, not only of the need to reduce emissions, but to realize the importance of adapting to the increasingly changing climate."
Some of the key findings of the study are summarized below.
*The Arctic climate is now warming rapidly, with human-induced changes in the region's climate among the largest on earth. Warming in the Arctic is projected to be around two or three times greater than the rest of the world. As a result, Arctic vegetation zones will likely shift, bringing wide-ranging impacts.
*The diversity, ranges, and distribution of animal species will change. Polar bears could become extinct by the end of this century. They are very unlikely to survive as a species if there is an almost complete loss of summer sea ice cover, which some climate models project will occur before the end of this century. As well, some arctic fisheries will disappear.
*New health hazards for both animals and humans are set to appear as the climate warms. Multiple influences will interact to affect both people and ecosystems. Elevated ultraviolet (UV) radiation levels, for example, will affect people, plants, and animals.
*A warmer climate is likely to lead to more forest fires and storm damage to coastal communities in the Arctic. Many coastal communities and facilities will face increasing exposure to storms.
*Reduced sea ice is very likely to increase marine transport and access to resources, while thawing ground will disrupt transportation, buildings, and other infrastructure.
*Arctic warming and its consequences will have global implications. The thawing of glaciers, sea ice and tundra will contribute to rising sea levels around the world. The report says sea levels could rise by nearly one metre by the end of the century. A warmer Arctic will contribute up to 15% of this rise. Some 17 million people now live less than one metre above sea level in Bangladesh alone, and low-lying places like Florida and Louisiana in the U.S., Bangkok, Calcutta, Dhaka and Manila are also at risk from rising sea levels.
*The area of the Greenland Ice Sheet that experiences some melting has increased by about 16% from 1979 to 2002. In 2002, the area of melting broke all previous records. Global warming could eventually cause the Greenland Ice Sheet to melt completely, resulting in a worldwide sea-level rise of seven metres, although this would take several hundred years.
*A melting Arctic will also accelerate the rate of global climate change. As arctic snow and ice melt, the ability of the Arctic to reflect heat back to space is reduced, accelerating the overall rate of global warming. In addition, a warmer Arctic could potentially halt the Gulf Stream, which brings warmer water and weather to northwestern Europe.
The four-year ACIA involved some 250 scientists from around the world. Canada's participation was led by Environment Canada, supported by other federal departments including Natural Resources Canada (NRCan), Fisheries and Oceans Canada (DFO), Indian and Northern Affairs Canada and Foreign Affairs Canada. The federal government also provided $500,000 in financial support to the ACIA, as part of its standing commitment to research and other initiatives designed to understand and respond to the impacts of climate change in Canada.
More than 40 Canadian scientists contributed to the assessment, with several of them among its lead authors. Canada's participation also included some 30 individuals from Arctic Aboriginal communities whose expertise in traditional knowledge made an important contribution to the assessment of climate impacts.
The ACIA is a project of the Arctic Council, a high-level, intergovernmental forum founded in Ottawa in 1996. The Council provides a mechanism to address the common concerns and challenges faced by the circumpolar nations: Canada, Denmark (including Greenland and the Faroe Islands), Finland, Iceland, Norway, the Russian Federation, Sweden and the U.S. The goal of the ACIA is to evaluate and synthesize knowledge on climate variability and change and increased ultraviolet radiation, and support policy-making processes and the work of the Intergovernmental Panel on Climate Change.
More information is available on Environment Canada's Green Lane, www.ec.gc.ca/EnviroZine/english/issues/48/feature1_e.cfm. The ACIA Overview, "Impacts of a Warming Arctic," is available for downloading in pdf format at www.acia.uaf.edu/.