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Climate change in Alaska

Climate change in the US state of Alaska

  • 10 min read
  • 4 chapters

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Through Glacier, Drainage basin and Energy conservation

With winter temperatures increasing, the type of precipitation will change. Lack of snow cover on the ground will expose tree roots to colder soils, and yellow cedar is already showing the result of this with many trees dying. The melting of glaciers in the watershed is likely to accelerate and will cause hydrological changes that will impact the wetland habitats and the distribution of wildlife. Animals such as the black-tailed deer, moose and mountain goat may benefit from less snow cover, while such mammals as the northwestern deer mouse that tunnels under the snow are likely to be disadvantaged.

The Alaska Climate Change Sub-Cabinet was established in 2006 to advise the Governor on climate change strategy, including opportunities to reduce greenhouse gas emissions through the use of alternative fuels, energy conservation, fuel efficiency, and transportation planning.

Observed effects of climate change

In August 2016, the Environmental Protection Agency (EPA) reported that "[o]ver the past 60 years, most of the state has warmed three degrees (F) on average and six degrees during winter" As a result of this temperature increase, the EPA noted that "Arctic sea ice is retreating, shores are eroding, glaciers are shrinking, permafrost is thawing, and insect outbreaks and wildfires are becoming more common". The EPA further noted that these changes were likely to accelerate in the future, potentially causing infrastructure damage due to thawing permafrost, and a decline of the state's fishing industry.

The temperate rainforest in southeast Alaska, in the Tongass National Forest is a perhumid (always wet) temperate rain forest. A perhumid temperate rainforest is a rainforest that receives above ten percent of its annual rainfall during the summer. Another contributing factor to define a perhumid rainforest is transient snow must be present in the winter with mean annual temperatures of 7 °C. These qualities define the rainforest as cool and temperate.

At present, the southeast Alaskan temperate rainforest is strongly dominated by old growth stands. The vegetation is strongly represented by a series of conifers; Sitka spruce, western hemlock, mountain hemlock, amabilis fir, shore pine, western red cedar, and Alaska yellow cedar. This forest, unlike its neighboring regions to the north and south, is completely safe from fires. Fire is virtually nonexistent in the southeast region due to the moist and cool climate. Small scale windthrow is the main disturbance that affects the rain forest in this region. Temperatures and precipitation in the southeast region of Alaska for the year of 2011 have matched what a typical temperate rainforest needs to be defined as one by DellaSala. Juneau, Alaska, received 2,940 millimeters (115.9 inches) of precipitation and averaged 40.6 °F during 2011. Snowfall, as will be discussed in further detail later, is an important player for the temperate rainforest in this region, and the Juneau area received 1,690 millimeters (66.4 inches) which, converted to its liquid equivalent is 294 millimeters (11.59 inches). The weather characteristics of the southeast region match up very well with what a temperate rainforest needs as defined by DellaSala.

Coastal erosion

A number of communities in Alaska are expected to be effected by coastal erosion and sea level rise. A 2009 report by the Government Accountability Office identified 21 communities at direct risk, and recommended their managed retreat. For example, Kivalina, Alaska will be inundated by 2025.

Trans-Alaska Pipeline System

Heavy rains in Alaska resulting from climate change have brought flooding close to the Trans-Alaska Pipeline System in recent years. In May 2019, the Dietrich River flooded north of Coldfoot, eroding 7.6–15.2 meters (25–50 feet) of riverbank, necessitating emergency work that left only an 80-foot buffer between the river and the pipeline. A few months later, in August, the Sagavanirktok River flooded, eroding 30 meters (100 feet) of river bank, and leaving only a 30-foot buffer between the river and the pipeline. The Lowe River also flooded near the pipeline in March 2019, and again in June 2020. Although Alyeska appears to be responding by stockpiling construction and emergency response materials, and has installed ground chillers beneath a stretch of pipeline 92 kilometers (57 miles) northwest of Fairbanks, comprehensive information on plans for addressing pipeline breaks in "high consequence areas" is not readily available.

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