Effects in Washington
See how warmer temperatures connect to other climate change effects in Washington:
  • Snow pack
  • Rising sea level
  • Extreme weather
  • Warmer Temperatures

    Scientists project average annual temperatures in the Pacific Northwest will be almost 2 degrees higher by the 2020s and almost 3 degrees higher by the 2040s, compared with 1970-1999 averages.
    Source: (University of Washington - Climate Impacts Group)

    Although that doesn’t sound like much, a warming climate means changing weather patterns. For Washington state, that’s expected to mean milder winters and hotter summers, which bring many other changes as well. For example, more rain and less snow is expected to fall from October through March, when water demands are lowest, and less rain is expected to fall in summer, when water needs are highest. Hotter summers will only increase the need for water for farms, fish and communities.

    Milder winters with more rain and hotter summers with less rain will change the usual living conditions for plants and animals, including people.


    Decline in water supplies

    dry reservoir

    Much of Washington's water supply is stored in snow pack and glaciers that melt into rivers. With less snow falling to replenish the frozen supply, and more months of warmer temperatures to melt it, there are impacts downstream:

    These impacts make it more difficult to meet the water supply needs of people and fish. This is especially critical in the state’s many snowmelt-fed watersheds with growing populations.

    See the Reduced Snow Pack web page for more.

    Sources:
    Scientific Forecast of Climate Change Effects in Washington State
    (Feb. 2009, Climate Impacts Group, University of Washington)

    An Overview of Potential Economic Costs to Washington of a Business-As-Usual Approach to Climate Change
    (Feb. 2009, Climate Leadership Initiative, University of Oregon)


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    More human health risks

    mosquito

    Heat-related illnesses and mortality are likely to increase when temperatures exceed thresholds of 100 degrees, especially without air conditioning and when nighttime temperatures remain high.

    Higher summer temperatures are likely to result in more smog in urban areas. Respiratory conditions are aggravated by smog, as well as by:

    As temperatures rise, Seattle, Spokane and other urban areas come closer to violating Clean Air Act standards.

    Increased carbon dioxide levels stimulate pollen production, which also aggravate respiratory allergies. Dust is a respiratory irritant more prevalent in regions with persistent drought.

    Warmer temperatures and weather extremes may play a role in expanding the range of diseases spread by insects, such as mosquitoes carrying West Nile Virus and ticks carrying Lyme disease.

    Source:
    An Overview of Potential Economic Costs to Washington of a Business-As-Usual Approach to Climate Change
    (Feb. 2009, Climate Leadership Initiative, University of Oregon) pg 62


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    Changing growing seasons

    irrigation

    With a warming climate, the growing season for some plants may be extended. The last frost would come earlier in the spring and first frost would come later in the fall. However, this advantage can be erased if there is limited water to nourish forests and crops during hot weather.

    Studies in Washington wine country conclude that more frequent series of extreme hot or cold days can result in damage and loss, even if the rest of the season is more moderate.

    Source:
    An Overview of Potential Economic Costs to Washington of a Business-As-Usual Approach to Climate Change (Feb. 2009, Climate Leadership Initiative, University of Oregon) pg 55


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    More pests in forests & crops

    beetle blight in a forest

    With warmer winters, pest populations can reproduce longer with less winter die-offs — so pest populations can boom.

    In northeastern Washington forests, pine bark beetles are rapidly devastating large tracts of forests. In British Columbia, Canada, more trees have been lost due to beetle infestation than to wildfires or logging, in an area three times the size of Maryland. Surveys show the beetle has infested 21 million acres and killed 411 million cubic feet of trees — double the annual harvest by all the loggers in Canada. In seven years or sooner, the Canadian Forest Service predicts that number will nearly triple. This loss of lodge pole pines will reshape the future of the forest and the communities it supports.

    Coddling moths and other orchard and agricultural pests can reproduce faster without cold winters.

    Shifting climate allows invasive plants and insects to move into new, warmer territory. Native species are stressed by unusual weather and water conditions to which they cannot rapidly adapt.

    Sources:
    Climate Impacts on Washington's Hydropower, Water Supply, Forests, Fish and Agriculture (Oct. 2005, Climate Impacts Group, University of Washington) pg 34

    Climate Impacts on Pacific Northwest Forests (Climate Impacts Group, University of Washington)

    Rapid Warming spreads havoc in Canada's forests (Mar. 2006, Washington Post)

    For more information:
    Forest Health Highlights in Washington — 2007, Pine Bark Beetles (2007, Department of Natural Resouces)

    Major Bark Beetles of the Intermountain West Washington (2003, Department of Natural Resouces)


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    Salmon declines

    jumping salmon

    Salmon and many other fish rely on timely, abundant, cold, clean water to spawn and rear young. Projected climate change would increase fall and winter flooding. As high river flows shift to earlier in the spring, salmon rearing, migration, and spawning will be negatively affected.

    Low flows in spring and summer result in warmer water which holds less oxygen and stresses fish. Increased summer stream temperatures may exceed tolerable limits for coldwater fish. Changing temperatures in lakes, Puget Sound, and the coastal ocean could decrease food for fish.

    During the drought of 2001, hundreds of thousands of juvenile salmon were stranded by low flows in the Columbia River and were unable to travel to the Pacific Ocean. In spring of 2005, above-average ocean temperatures and reduced ocean movement resulted in a 20-30 percent drop in juvenile marine salmon populations.

    A 50-year warming trend in Lake Washington has reduced the food available for fish and caused algae blooms. High stream temperatures in 2004 were implicated in major sockeye salmon die-offs in the Fraser River.

    Sources:
    Fish & Shellfish, King Co. Climate Conference 2005 (2005, Climate Impacts Group, University of Washington)

    Scientific Forecast of Climate Change Effects in Washington State
    (Feb. 2009, Climate Impacts Group, University of Washington) pg 35

    An Overview of Potential Economic Costs to Washington of a Business-As-Usual Approach to Climate Change
    (Feb. 2009, Climate Leadership Initiative, University of Oregon) pg 76


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    Native plant & animal populations decline

    orca whale

    Shifting climate allows invasive plants, animals and insects to move into new, warmer territories. Native species are stressed by unusual weather and water conditions to which they cannot rapidly adapt. Extinction of local animals, and potentially entire species, are expected with climate change.

    Plant communities undergo shifts in their species composition and/or numbers.

    As the ecosystem changes, the historic linkages between predator and prey migrations, or bloom times and pollinators, can shift out of sync, causing ripple effects across the system. Population booms or crashes can affect the rest of the system.

    Source:
    Climate Impacts on Pacific Northwest Forests (Climate Impacts Group, University of Washington)


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    Wetlands decline

    child at an aquarium

    As the effects of global warming become more apparent, the value of – and the threat to – our wetlands increases. Depending on their location in the state, wetlands are in danger of being flooded out, dried up, or relocated. The benefits of wetlands and their surrounding areas include:

    Source:
    Issue up Close: Sustaining our remaining wetlands for people, fish and wildlife (2006, Department of Ecology)