- Impacts of climate change
- King County's response
- State Environmental Policy Act
- Additional information
Human activities are the most significant factor in the striking increase in atmospheric greenhouse gases (GHGs) over the last century. Increased GHG levels are the primary cause of human-caused climate change.
The impacts of climate change are often associated with problems in far away parts of the world, some time in the future. Sea level rise in low lying countries, damage to coral reefs, melting ice caps, the spread of insect borne disease and increases in drought are just some of these impacts that are linked to climate change.
However, there are significant and critical impacts from climate change that are already occurring in the Pacific Northwest that are very likely to increase in severity; these are often less well known and are briefly highlighted here.
Climate change is likely to have the following impacts in the Pacific Northwest:
Water and snow
- Decreased water for irrigation, fish, and summertime hydropower production and increased urban demand for water, leading to increased conflicts over the resource.
- Warmer winter temperatures and increased winter precipitation are projected to reduce the winter snowpack. This will also delay the opening of the ski season, shorten the length of the season, and increase the likelihood of rain when ski areas are open. The impacts are greater for mid-elevation ski areas (~3,000 to 4,000 feet) than for those at higher elevations.
- Increased difficulties for migration and spawning due to increased winter floods, decreased summer streamflow, and increased water temperatures.
- Potential increases in forest fires.
- Overall, the Pacific Northwest is likely to see increased forest growth region-wide over the next few decades followed by decreased forest growth as temperature increases overwhelm the ability of trees to make use of higher winter precipitation and higher carbon dioxide.
- Potential for extinction of local populations and loss of biological diversity if environmental shifts outpace species migration rates and interact negatively with population dynamics.
Coastal Flooding and Erosion
- Increased coastal erosion and beach loss due to rising sea levels
- Increased landslides due to increased winter rainfall
- Permanent inundation, especially in south Puget Sound around Olympia
- Increased coastal flooding due to sea level rise and increased winter streamflow from interior and coastal watersheds.
- Many crops will grow better with higher CO2 and a longer growing season before temperatures substantially increase, provided there is sufficient water. However, some pests and weeds will be similarly advantaged. Low-value irrigated crops may have difficulty competing for less abundant water.
King County has taken a number of actions to begin addressing the challenges presented by climate change. These actions include:
- Confronting climate change
- The King County Strategic Climate Action Plan. The 2015 SCAP is a five-year blueprint for County action to confront climate change, integrating climate change into all areas of County operations and its work in the community.
- Past reports and plans
- Beyond carbon neutral
- Development of the Preparing for Climate Change Guidebook in conjunction with the University of Washington's Climate Impacts Group and ICLEI-Local Governments for Sustainability.
The Washington State Environmental Policy Act (SEPA) requires environmental review of development proposals that may have a significant adverse impact on the environment.
If a proposed development is subject to SEPA, the project proponent is required to complete the SEPA checklist. The checklist includes questions relating to the development's air emissions. The emissions that have traditionally been considered cover smoke, dust, and industrial and automobile emissions.
King County is the first local government in the nation to officially add greenhouse gas emissions to the environmental review of construction projects. King County's policy covers projects undergoing environmental review mandated by the SEPA and applies to the County's own developments as well as projects where the County is the lead permitting agency.
GHG emissions associated with development come from multiple sources:
- The extraction, processing, transportation, construction and disposal of building materials
- Landscape disturbance
- Energy demands created by the development after it is completed
- Transportation demands created by the development after it is completed.
King County has developed a SEPA Greenhouse Gas (GHG) Emissions Worksheet that can assist applicants in answering the SEPA checklist question relating to GHG emissions.
The SEPA GHG emissions worksheet estimates all GHG emissions that will be created over the life span of a building project. This includes emissions associated with obtaining construction materials, fuel used during construction, energy consumed during the buildings operation, and transportation by building occupants.
- Permitting Department SEPA application packet
- Permitting Department SEPA Checklist
- The King County Executive's Confronting Global Climate Change priority area
- King County Green Tools
- World Meteorological Organization and United Nations Environment Programme Intergovernmental Panel on Climate Change, Working Group I: The Physical Basis of Climate Change
- University of Washington Climate Impacts Group: Washington Climate Change Impacts Assessment