Report Released Detailing Climate Change Implications For Washington State: Snowpack To Decline By 38-46 Percent By 2050

The University of Washington’s Climate Impacts Group has released “Shifting Snowlines and Shorelines: The Intergovernmental Panel on Climate Change’s Special Report on the Ocean and Cryosphere and Implications for Washington State.”

In the brief, the CIG compresses the dense 1,170-page IPCC Special Report on the Oceans & Cryosphere into nine pages of text and figures that “bring the global science down to the local level.”  

The brief includes information about:

• How climate change is altering oceans and the Earth’s frozen regions, both globally and for glaciers, oceans and snowfall across Washington state

• The environmental, financial and social costs of these changes

• Implications of additional warming

• How the region can prepare for these impacts.

In Washington State, the impacts of a changing cryosphere and warming ocean are already being felt.

The brief says:

Warming has affected Washington’s ocean and cryosphere, with consequences for agriculture, water resources, infrastructure, transportation, recreation and livelihoods across the state.

Washington’s glaciers and snowpack are in decline. Sea levels are rising. Coastal and marine ecosystems are responding to increased ocean heat and biogeochemical changes.

During 2014-2016, a ‘Blob’ of unusually warm Pacific Ocean water off the United States west coast resulted in large areas with sea surface temperatures 3.6ºF (2ºC) above average, causing seabird and marine mammal die-offs.

In 2015, when Washington experienced a drought driven by historically low winter snowpack, 17 major crops experienced reduced yields from limited water availability and higher temperatures, fisheries closed due to warmer waters and reduced streamflows, and the ski season at Stevens Pass was 42% shorter than in previous years. Years like 2015 foreshadow the expected local impacts of continued warming.

Continued global warming will lead to accelerating sea level rise, additional ocean acidification, declines in snowpack and loss of glaciers in Washington state, with negative consequences for ecosystems, communities and industries that are critical to local cultures and livelihoods.

Washington’s coastal waters will continue to acidify throughout the 21st century. Acidification and accelerating ocean warming will compromise the growth, reproduction and survival of nearly a third of Washington’s nearshore coastal species.

The negative effects of ocean warming and acidification on fisheries and shellfish like clams, oysters and mussels could lead to more fisheries closures with substantial economic and cultural consequences for both commercial and subsistence fisheries and coastal communities.

Sea surface temperatures off Washington’s coast are projected to increase about 2.2°F (1.2ºC) by the 2040s (relative to 1970–1999). This is expected to make harmful algal blooms (HABs) more likely to occur. By the end of the century under a moderate greenhouse gas emissions scenario (A1B), warmer waters in the Puget Sound are expected to lead to an average of 13 more days per year with favorable conditions for HABs. The season suitable for HABs would begin up to two months earlier and last up to one month longer than in the past (1970–1999). HABs are a threat to human and marine health and commercial and subsistence fisheries.

Glacier retreat and reductions in mountain snowpack are projected to affect Washington’s water resources, recreation, hydropower production and irrigated agriculture. Statewide average spring snowpack is projected to decline 38 to 46% by mid-century and 56 to 70% by the 2080s (relative to 1970–1999) under low (B1) and moderate (A1B) greenhouse gas scenarios, respectively.

Warmer winters, less snow and a greater proportion of winter precipitation falling as rain are projected to shift the timing of peak spring streamflow to earlier in the year, increasing the risk of wintertime flooding and decreasing summer streamflows and natural summer water availability.

Rising seas will increase coastal flooding, inundation, salt-water intrusion and bluff erosion across coastal Washington. Sea level rise is expected to threaten public and private coastal properties, low-lying agricultural lands and roads and alter coastal habitat. Relative sea level is projected to increase across coastal Washington, with different communities experiencing different amounts of change based on their geographic and geologic setting.

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