Alaska Climate Change Adaptation Series ACC-00115 Regional Climate Projections: Southwest Alaska and Aleutian Islands

This region encompasses the Aleutian Islands, with a maritime climate, and the southwest coast, a region of maritime influence. Though mean annual temperatures are similar to inland sites at the same latitudes, the seasonal range of temperatures is much lower and the winds are much higher, yielding ecosystems dominated by grasslands and shrubs rather than forests. As temperatures increase, loss of permafrost and shorter seasons for land-fast ice will exacerbate the erosion caused by coastal storms. Both terrestrial and marine ecosystem shifts are likely.

Who We Are ACCAP — The aim of the Alaska planations of the uncertainty inherent Center for Climate Assessment and in all forms of forecasting. SNAP — The Scenarios Network for Policy is to assess the socioeconomic Alaska & Arctic Planning links universi- and biophysical impacts of climate Uncertainty ty researchers with communities and variability in Alaska, make this infor- While values are based on the best resource managers. Through partner- mation available to decision makers, ships involving data sharing, research, available climate models, they are es- and improve the ability of Alaskans to timates only. There is variation among modeling and interpretation of model adapt to a changing climate. results, SNAP addresses some of the climate models and annual variation within each model. Interpretation of complex challenges of adapting to Together, SNAP, ACCAP and CES impacts adds additional uncertainty. future conditions. provide a variety of services that may assist you in meeting your community Climate Models CES — The Cooperative Extension planning needs. Service is the educational outreach SNAP provides average values of pro- component of the national land grant Planning for Change jections from five global models used university system — in Alaska, the Alaskans face many challenges in the by the Intergovernmental Panel on University of Alaska Fairbanks. CES next century. Rising energy costs have Climate Change (IPCC). Climate pro- conducts research and provides edu- impacted the cost of food, fuel and jections are based on three scenarios cational outreach statewide. other services. Changes in tempera- for carbon dioxide emissions that ture and moisture can trigger pro- cover a wide range of possible future found landscape-level changes such conditions. as sea level rise, modified patterns of storms, flooding or fire, and altered Statewide Trends migration routes, breeding patterns or Temperatures and precipitation are survivorship of fish and wildlife. expected to increase across the state throughout the next century. The Everyone — from engineers to growing season will lengthen, and gla- farmers to wildlife managers — will UNIVERSITY OF ALASKA FAIRBANKS ciers, sea ice and permafrost will be need to take economic change, social reduced. Significant ecosystem shifts change and climate change into are likely statewide. account when planning for the future in order to avoid costly mistakes and www.uaf.edu/ces take advantage of new opportunities. 1-877-520-5211 Planning requires objective analysis of future projections, including clear ex- www.snap.uaf.edu Climate Projections Temperatures in this region are projected to increase, resulting in a transition from average annual temperatures near the freezing point to temperatures well above the freezing point. In many parts of the Aleutians, decreased (or completely absent) snow- fall may occur as the mean winter temperature rises above freezing. Precipitation is also projected to increase throughout Southwest Alaska and lem, although coastal areas that are are driven out by changes to habi- across the Aleutian chain, and win- historically free of sea ice, which in- tat, higher temperatures allow other ter precipitation may increase by as cludes the Aleutian Islands, probably animals such as fur seals and Steller much as 19 percent by the end of the will not experience the more extreme sea lions to remain on the islands century. erosion of more northern regions. throughout the winter. Regional Impacts Higher ocean temperatures are Lack of hard frost may also drive spe- altering the Bering Sea ecosystem, cies shifts and allow invasive species Increased incidence and severity of impacting marine mammals, fish and to encroach, although more remote storms are of significant concern in birds. Nonindigenous warm-water fish islands may be less susceptible than this region. Southwest Alaska has species have already been observed other parts of the state. It is possible also seen a decline in shore ice in the in the North Pacific and Bering Sea. that some species shifts may not occur winter, making coastal villages more Large northward shifts in fish and as rapidly as needed to keep up with vulnerable to winter storm wave shellfish species are expected, and it changing climate conditions. Tree line action. In Nelson Lagoon, for instance, may become necessary to relocate will continue to move westward as the breakwall designed to brace shore fisheries infrastructure. wet tundra areas dry. ice provides little protection against the full force of storm waves. Subsistence hunting and fishing could be impacted in positive and negative As a result of sea level rise and storm ways. While some animal species surges, erosion may also be a prob-

The chart tool used to create these graphs is available for more than 440 communities statewide at www.snap.uaf.edu.

Published by the University of Alaska Fairbanks Cooperative Extension Service in cooperation with the United States Department of Agriculture. The University of Alaska is an AA/EO employer and educational institution and prohibits illegal discrimination against any individual: www.alaska. edu/titleIXcompliance/nondiscrimination. ©2013 University of Alaska Fairbanks. 6-13/SNAP-ACCAP/6-13 New June 2013