Overview

Sea ice has already declined considerably over the past half century. Additional declines of roughly 10-50% in annual average sea-ice extent are projected by 2100. Loss of sea ice during summer is projected to be considerably greater than the annual average decrease, with a 5-model average projecting more than a 50% decline by the end of this century, and some models showing near-complete disappearance of summer sea ice. The projected reductions in sea ice will increase regional and global warming by reducing the reflectivity of the ocean surface. (Source: Arctic Climate Impact Assessment)

The Arctic Climate Impact Assessment (ACIA) is an international project of the Arctic Council and the International Arctic Science Committee (IASC), to evaluate and synthesize knowledge on climate variability, climate change, and increased ultraviolet radiation and their consequences. The results of the assessment were released at the ACIA International Scientific Symposium held in Reykjavik, Iceland in November 2004.

The Arctic Council is a high-level intergovernmental forum. The members are Canada, Denmark, Finland, Iceland, Norway, the Russian Federation, Sweden, and the United States of America. The International Arctic Science Committee (IASC) is a non-governmental organization that facilitates cooperation in all aspects of arctic research in all countries engaged in arctic research and in all areas of the arctic region.

The ACIA Secretariat was hosted at the International Arctic Research Center at the University of Alaska Fairbanks. Funding for the Secretariat was provided by the U.S. National Science Foundation (NSF) and the National Oceanic and Atmospheric Administration (NOAA).

The ACIA aims is to provide useful and reliable information to the governments, organizations and peoples of the Arctic on policy options to meet such changes. Climate variability and change, and more recently, notable increases in UV radiation, have become important issues in the Arctic over the past few decades. The ACIA will examine possible future impacts on the environment and its living resources, on human health, and on buildings, roads and other infrastructure. Such an assessment is expected to lead to the development of fundamental and useful information for the nations of the Arctic region, their economy, resources, and peoples.

The U.S. is the lead country for this effort and representatives from NSF and NOAA will also be members of the Assessment Steering Committee (ASC). Its chairman is Dr. Robert Corell from the U.S., and the Vice-Chair is Dr. Pal Prestrud from Norway. Close ties will be maintained with the group conducting a similar regional assessment as part of the Intergovernmental Panel on Climate Change (IPCC) but it is expected that the ACIA will provide considerably more detail on the expected impacts.

Summary of Findings

• Arctic climate is now warming rapidly and much larger changes are projected
• Arctic warming and its consequences have global implications.
• Arctic vegetation zones are very likely to shift, casing wide-ranging impacts.
• Animal species’ diversity, ranges, and distribution will change.
• Reduced sea ice will increase marine transport.
• Thawing ground will disrupt transportation, buildings and other infrastructure.
• Indigenous communities are facing economic and cultural impacts.
• Increased ultraviolet radiation will affect people, plants and animals.

Further reading

• Arctic Climate Impact Assessment home page
• The Arctic Portal