Assessing the Impact of Climate Change on Alaska

Alaska, like many other areas of the world, experienced a shift to warmer temperatures in the late 1970s. The magnitude of this recent shift, as well as the rate of climate warming and projected future changes, pose a host of problems and opportunities, some with international economic implications, for the people of Alaska.

Melting permafrost is altering the boreal forest near Tok, Alaska. Photo courtesy of T. Osterkamp, University of Alaska, Fairbanks

ALASKA – RECENT CLIMATE-RELATED IMPACTS Increases in salmon catches. Increased road maintenance costs and major landscape changes from accelerated thawing of permafrost. Fewer construction problems where permafrost has melted. Longer growing season for forestry and agriculture. Subsistence hunting patterns have shifted; with changes in sea ice conditions hunting on the ice has become more dangerous. Permafrost thawing has ruined the traditional ice cellars of northern villages. Warmer conditions have allowed insects to thrive when cooler summers and colder winters would have normally held them in check; for example, the spruce bark beetle has destroyed around three million acres of forest. Spring ice breakups on the Tanana River are occurring earlier.

Such changes are also having an impact on the infrastructure presently in place, and may affect the chances of survival of Alaska’s forest and other ecosystems, the goods and services of which are crucial to the region. Among the major climate-related trends in Alaska that scientists have observed are the following:

Air temperatures for Barrow, Nome, Fairbanks, and Anchorage increased two degrees C. around 1977 and the increases have persisted. The extent of sea ice decreased about five percent in 1977 and has remained that way; sea ice thickness may also have been reduced. Precipitation has increased for most of Alaska, except for the southeastern part of the state and summer precipitation in the interior, particularly around Fairbanks.

Boreholes reveal that permafrost temperatures in northern Alaska have increased two to four degrees C. above temperatures 50-110 years ago; permafrost has thawed in some places where it is discontinuous. The 30-year air temperature record shows that increases are greatest in winter and spring and in the interior of Alaska and north of the Brooks Range.

The Interior-sponsored Alaska workshop–held in June 1997–drew people from within as well as outside of the state to discuss current and potential problems associated with the state’s forests, tundra, marine resources, wildlife, subsistence economy, coastal systems, permafrost, and human systems–such as transportation, energy, and land use–under changing climate scenarios.

With further warming in Alaska, a variety of consequences are possible. The location, volume, and species mix of fish catches could change, causing stress as the industry deals with relocation of harvesters and processors. While the permafrost is melting, the maintenance cost for pipelines could increase, but construction costs could decline once it is melted. The loss of sea ice could reduce oil and gas offshore exploration and production costs and improve shipping, but coastal erosion could increase due to higher sea levels and increased storm intensity.

A longer growing season could improve agriculture and forestry yields but warmer temperatures and increased summer drying could increase flammable vegetation, thus increasing the potential for more forest fires. While warmer weather could bring a longer tourist season, degraded attractions due to melted glaciers and fires could offset the benefit. A warmer climate could also result in changes in the need for government services as local income declines due to a decline or loss of subsistence resources. 

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Source: United States Geological Survery Report 2006