Alaska Impacts & Adaptation

Climate Impacts on Alaska

Alaska is a huge state with a wide range of climatic and ecological conditions. It is known for its rainforests, glaciers, boreal forest, tundra, peatlands, and meadows. Alaska contains 75% of U.S. national parks and 90% of U.S. wildlife refuges, by area. ^[1]

Over the past 50 years, temperatures across Alaska increased by an average of 3.4°F. Winter warming was even greater, rising by an average of 6.3°F. ^[2] The rate of warming in Alaska was twice the national average over that same period of time. Average annual temperatures in Alaska are projected to increase an additional 3.5 to 7°F by the middle of this century. ^[2]

Precipitation in Alaska has also increased slightly, but the trend is not significant. Climate projections indicate that Alaskan winters are likely to be wetter, and that summers could become drier, as rising air temperatures accelerate the rate of evaporation. ^{[2] [3]}

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Permafrost Impacts

Permafrost is the frozen ground located one to two feet below the surface in cold regions. As permafrost thaws and the soil sinks, structures built on or within the soil are damaged. Although most Alaskans live in permafrost-free areas, an estimated 100,000 Alaskans (about 14% of the population) live in areas sensitive to permafrost degradation. ^[4] As explained below, the impacts of melting permafrost on transportation, forests, ecosystems, and the economy could have widespread implications for Alaskans.

Permafrost Impacts on Transportation

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Alaska highways susceptible to permafrost. Source: U.S. Arctic Research Commission (2003)

Permafrost thawing and cycles of freezing and thawing can cause extensive damage to highways, railroads, airstrips, and other transportation infrastructure in Alaska.

Alaska's "drunken forests" — as permafrost thaws, trees lean into the ground. Source: USGCRP (2009) (PDF)

Many of Alaska's highways are built on permafrost. When permafrost thaws, roads buckle. Vehicles are only allowed to drive across certain roads in the tundra when the ground is frozen solid. In the past 30 years, the number of days when travel is allowed on the tundra has decreased from 200 days to 100 days per year. ^[2] Projected increases in temperatures and permafrost thawing would continue this trend and could further limit access to the tundra. Building infrastructure on thawing permafrost requires additional engineering, and can increase the cost of construction by 10% or more. ^[2]

For more information on climate change impacts on transportation, please visit the Transportation Impacts page.

Permafrost Impacts on Forests

As temperatures rise and permafrost thaws, the softening soil interferes with tree root systems. The altered soil conditions cause trees to sink into the ground. As a result, the trees in many of Alaska's forests lean, creating so-called "drunken forests." ^{[2] [3]}

For more information on climate change impacts on forests, please visit the Forest Impacts page.

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Pond shrinkage in Alaska's Yukon Flats National Wildlife Refuge, 1951-2000. Source: USGCRP (2009)

Permafrost Impacts on Ecosystems

Over the past 50 years, thawing permafrost and increased evaporation have caused a substantial decline in the area of Alaska's closed-basin lakes (lakes without stream inputs and outputs). These surface waters and wetlands provide breeding habitat for millions of waterfowl and shorebirds that winter in the lower 48 states. ^[2] These wetland ecosystems and the wildlife resources are important to Alaska Natives who hunt and fish for food.

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Other Impacts on Ecosystems

As the climate warms, shrubs are invading the tundra. In some areas, the shrubs are replacing lichens and other tundra vegetation. Lichens are an important winter food source for caribou, and the loss of lichens can lead to declines in the growth and abundance of these animals. Caribou in turn are a critical food source for predators such as bears and wolves, as well as for Alaska Natives. ^[3]

Higher temperatures and less summer moisture increase the risks of drought, wildfire, and insect infestation. Alaska's boreal spruce forest declined substantially in recent decades from both fire and insect damage. By mid-century, the average area burned by wildfire each year is likely to double. ^[2]

For more information on climate change impacts on ecosystems, please visit the Ecosystems Impacts page. For more information on climate change impacts on forests, please visit the Forest Impacts page.

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Monthly September sea ice extent for 1979-2010 shows a decline of 12% per decade. Source: National Snow and Ice Data Center (2010)

Impacts on Oceans and Coasts

The extent of sea ice is declining throughout the Arctic. Sea ice is frozen seawater floating on the surface of the ocean. Some sea ice persists from year to year (known as perennial sea ice), often getting thicker as it piles up against Arctic shorelines. Other sea ice melts during the warm season and refreezes in the cold season. Over the past several decades, the perennial sea ice has declined dramatically. This decline is, in part, a result of extended periods of above-freezing air or water temperatures. Ocean currents and winds have also played an important role, pushing perennial sea ice out of the Arctic basin. The average sea ice extent in September has decreased by 11.5% per decade over the past 30 years. Climate models project that sea ice will continue to retreat during the 21st century. Late summers could be nearly ice-free as early as about the 2040s. ^[5]

Diminishing sea ice has opened new opportunities for shipping, oil and gas exploration, and other economic activities. However, it has also created a pathway for invasive species and caused the loss of critical habitat for a variety of ice-dependent species, including walruses and polar bears. Changes in sea ice can also affect the timing and location of plankton blooms, which can in turn affect the areas where commercial fisheries can thrive. Landfast ice (sea ice that has frozen along the shore) is important because it protects coastal shorelines and human settlements from flooding and erosion caused by storms, wind, and wave damage. ^{[2] [3] [5] [6]}

For more information on climate change impacts on coasts, please visit the Coastal Impacts page.

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Impacts on Alaska Natives

People in Alaska are already feeling the impact of climate change. In many parts of the state, the changing climate has negatively affected the livelihood, settlements, and well-being of residents. Alaska Natives fish in ocean and inland waters. They also hunt animals such as polar bears, walruses, seals, and caribou for food. As climate change reduces these species' critical habitats, declines in their population threaten not only the livelihood of Alaska Natives, but also their cultural and social identity. As the supply of fish and game declines, hunters and fishers are forced to seek alternative sources of food. ^{[2] [3]}

Ground under home in Shishmaref, Alaska collapsing from erosion. Source: Alaska Conservation Foundation (2010)

Along Alaska's northwestern coast, increased coastal erosion is causing some shorelines to retreat at rates averaging tens of feet per year. ^[2] Here, melting sea ice has reduced natural coastal protection. In Shishmaref, Kivalina, and other Alaska Native Villages, erosion has caused homes to collapse into the sea. Severe erosion has forced some Alaska Native Villages' populations to relocate in order to protect lives and property. ^{[2] [7]}

For more information on climate change impacts on society, please visit the Society Impacts page. For information about relocation efforts in Alaska, visit the Alaska Adaptation section.

To learn more about what Alaska is doing to adapt to climate change impacts, please visit the adaptation section of the Alaska Impacts and Adaptation page.

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References

[1] USGCRP (2000). Climate Change Impacts in the United States: The Potential Consequences of Climate Variability and Change . United States Global Change Research Program. Cambridge University Press, Cambridge, United Kingdom.

[2] USGCRP (2009). Global Climate Change Impacts in the United States . Karl, T. R., J. M. Melillo, and T. C. Peterson (eds.). United States Global Change Research Program. Cambridge University Press, New York, NY, USA.

[3] ACIA (2004). Impacts of a Warming Arctic: Arctic Climate Impact Assessment . Arctic Climate Impact Assessment. Cambridge University Press, Cambridge, United Kingdom.

[4] USARC (2003). Climate Change, Permafrost, and Impacts on Civil Infrastructure (PDF, 72 pp, 4.8MB) U.S. Arctic Research Commission, Arlington, VA, USA.

[5] NRC (2011). Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia . National Research Council. The National Academies Press, Washington, DC, USA.

[6] Anisimov, O.A., D.G. Vaughan, T.V. Callaghan, C. Furgal, H. Marchant, T.D. Prowse, H. Vilhjálmsson and J.E. Walsh (2007). Polar regions (Arctic and Antarctic). In: Climate Change 2007: Impacts, Adaptation and Vulnerability . Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change Parry, M.L., O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson (eds.). Cambridge University Press, Cambridge, United Kingdom.

[7] Alaska Climate Impact Assessment Commission (2008). Final Commission Report . Alaska State Legislature.

Efforts to prepare for climate change are underway in Alaska, a large state with a wide range of climatic and ecological conditions. Alaska is already experiencing the impacts of climate change due to the fact that, over the last fifty years, the state has been warming at a rate twice the national average. ^[1] Alaska will likely continue to face impacts from climate change, including the thawing of permafrost and increased coastal erosion from the loss of sea ice. Learn more about climate change impacts on Alaska here.

Below are examples of ongoing efforts to adapt to climate change impacts in Alaska at the local, state, and federal level. Following the examples is a list of links to a number of adaptation plans, reports, and studies specific to the region. Both the examples and links are intended to be illustrative — they are not intended to be comprehensive.

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Homer, Alaska takes a local approach to climate adaptation

Homer, Alaska is a small city that lies along the shore of Kachemak Bay, 125 miles southwest of Anchorage. At the end of 2007, the city's Global Warming Task Force released the Homer Climate Action Plan . The Plan identifies several climate change concerns for the city, including negative impacts on local fisheries and fresh water supply, severe storms, and increased risk of wildfire. ^[2] The Plan's adaptation strategies cover steps for fostering a resilient local economy, incorporating climate change impacts into emergency preparedness, and incorporating climate change into building and maintenance plans, especially along Homer Spit.

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Coastal Alaska Native Villages plan for relocation

The impact of climate change on sea ice threatens to worsen flooding and erosion which have historically been problems for many Alaskan communities. The U.S. Army Corps of Engineers identified 178 Alaskan communities that are threatened by erosion and 26 that are "Priority Action Communities." ^[3] Many of these communities are Alaska Native Villages. ^[4] Although sea walls and similar structures may protect some communities, other communities are forced to relocate. Severe erosion in Shishmaref, Kivalina, and Newtok has already driven these communities to develop relocation plans. ^[3]

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Coastal communities in peril from flooding and erosion: Flooding in Newtok, Alaska. Source: Alaska Department of Environmental Conservation.

• Due to substantial ongoing erosion, Kivalina , is working with several federal agencies, including the U.S. Army Corps of Engineers and the U.S. Department of Transportation, to determine the best option for relocation.
• In 2006, the Newtok Planning Group (comprised of state and federal agencies and non-governmental organizations) assisted the village of Newtok in making the decision to move to a new location (Mertarvik), several miles away.
• Shishmaref, a contemporary Inupiaq community located on a small barrier island, is working with the U.S. Army Corps of Engineers to relocate to the nearby mainland (see Shishmaref Erosion & Relocation Coalition ).

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Alaska State Government plans for climate change

In 2007, Governor Sarah Palin established the Alaska Climate Change Subcabinet to develop recommendations for a state climate change strategy. The Adaptation Advisory Group within the Subcabinet released Alaska's Climate Change Strategy: Addressing Impacts in Alaska in January 2010. In addition, other efforts are underway to respond to and prepare for various state climate impacts. For example, the 16 National Wildlife Refuges in Alaska are identifying and protecting lands that will provide critical resources for species migrations and reproductive activities in the future. ^[5]

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The U.S. Navy prepares for a more navigable Arctic

Canadian Coast Guard Ship Louis S. St. Laurent (left) and U.S. Coast Guard Cutter Healy (right) on the Arctic Ocean". Source: "Jessica K. Robertson, USGS, Alaska Department of Environmental Conservation.

As sea ice declines, the Arctic Ocean will become more accessible for trade and the extraction of natural resources. In November 2009, the Navy released an Arctic Roadmap that provides a timeline of actions including assessment of readiness to operate in Arctic conditions, disaster relief response exercises, promoting partnerships with other stakeholders, and improving environmental understanding. It is a five-year plan that will be revised in 2013 in accordance with guidance from the next Quadrennial Defense Review.

Other Climate Change Concerns for the Navy

In addition to the Arctic Roadmap, the Navy released a Climate Change Roadmap in May 2010. This document outlines the Navy approach to assessing, predicting, and adapting to climate change in regions other than the Arctic. It emphasizes collaborative partnerships and adaptation to reduce risk associated with sea level rise and changing environments.

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References

[1] USGCRP (2009). Global Climate Change Impacts in the United States . Karl, T. R., J. M. Melillo, and T. C. Peterson (eds.). United States Global Change Research Program. Cambridge University Press, New York, NY, USA.

[2] City of Homer, Alaska (2007). Homer Climate Action Plan .

[3] U.S. Army Corps of Engineers (2009). Alaska Baseline Erosion Assessment .

[4] U.S. General Accounting Office (2003). Alaska Native Villages — Most are Affected by Flooding and Erosion, but Few Qualify for Federal Assistance (PDF) (pp. 91, 5.25 MB). GAO Highlights

[5] CCSP (2008). Preliminary Review of Adaptation Options for Climate-Sensitive Ecosystems and Resources . A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. Julius, S.H., and J.M. West (eds.). U.S. Environmental Protection Agency, Washington, DC, USA.