HR: 10:22h
AN: A42A-01 INVITED     [Abstracts]
TI: Evidence for Arctic Climate Change
AU: * Corell, R W
EM: global@dmv.com
AF: American Meteorological Society, 1120 G Street, N.W. Suite 800 , Washington, DC 20005 United States
AU: Walsh, J E
EM: walsh@atmos.uiuc.edu
AF: University of Alaska Fairbanks, International Arctic Research Center, Fairbanks, AK 99775 United States
AB: Climate variability and change has become important issues in the Arctic over the past few decades. The Arctic Climate Impact Assessment (ACIA), a four-year scientific assessment of climate change of the Arctic, was established and charged to (i) evaluate and synthesize knowledge on the impacts and consequences of climate variability and change and increased ultraviolet radiation across the Arctic region, and (ii) support decision and policy making processes for the eight Arctic countries and their residents. This paper will provide an overview of the key findings from the scientific aspects of the Assessment. Past and present results are based on published data and information while the projections are based on five of the IPCC models driven by the B2, and in some cases A2, IPCC scenarios. Examples of the key findings are: Arctic climate is changing rapidly: Average Arctic temperature has risen by about 1øC in the past 100 years, nearly twice the global average, with the steepest increase in the last three decades. Accelerating climate changes are projected: The Arctic is very likely to warm an additional 3-9øC over the next 100 years, about twice the projected global average. Further, precipitation is likely to increase by about 8% by mid-century and 20% by the end of the century. Regional variations are observed and projected: Some parts of the Arctic have warmed more than others (e.g., some parts of Alaska have warmed at 5-10 times the global average over the past 30 years) while some have even cooled slightly. Arctic processes amplify global change: Melting of reflective Arctic snow and ice increases heat absorption of the exposed land and ocean, further warming the planet. Increases in glacial melt, precipitation and river runoff bring more freshwater to the ocean, raising sea level globally. Warming of Arctic soils and coastal oceans is likely to lead to increased release of carbon dioxide and methane. Reduced sea ice will enhance shipping opportunities: Sea ice retreat is very likely to seasonally open the Northeast and Northwest passages, making trans-Arctic shipping during summer possible within a few decades. Permafrost thawing will impact infrastructure: Climate change is likely to have significant impacts on existing buildings, roads, pipelines, and industrial facilities. Transportation on land will increasingly be disrupted by the failure of ice roads and tundra to freeze sufficiently to permit travel. Risks to many coastal areas will increase: Coastal erosion will be a growing problem do to substantial reductions in coastal sea ice in the spring and fall, which allows higher storm surges to reach shore which when combined with thawing coastal permafrost adds to the vulnerability of these coastlines. The Assessment has been completed and two peer-reviewed scientific documents (an Overview document and the complete scientific assessment0 will be available from Cambridge University Press by the end of the year (2004).
UR: http://www.acia.uaf.edu
DE: 3349 Polar meteorology
DE: 4215 Climate and interannual variability (3309)
DE: 3309 Climatology (1620)
DE: 1600 GLOBAL CHANGE (New category)
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting