Third Oregon Climate Assessment Report (OCAR3)

The Third Oregon Climate Assessment Report (OCAR3) released in January 2017 summarizes current climate change science and impacts for Oregon, while building on the previous assessment reports from 2010 and 2013. The legislatively mandated report was produced by the Oregon Climate Change Research Institute at Oregon State University in response to Oregon House Bill 3543 - “Global Warming Actions” - which requires a bi-annual assessment to the Legislative Assembly and Governor by the Research Institute with the likely effects of climate change on the state.

The majority of this third assessment covers key climate change risks facing Oregon and the Pacific Northwest, primarily for water resources, forest ecosystems, and coastal issues. The 3rd assessment has more regionally specific details, and economic analyses are included for some sectors.

According to the authors, the depth of the current assessment is intentionally less than in previous assessments as the previous assessments provide “rich content that is still pertinent and useful” - and should be utilized along with the 3rd assessment.

OCAR details the climate change impacts in Oregon with a chapter for each of the sectors:

  • Water,
  • Coastal,
  • Forest Ecosystems,
  • Agriculture, and
  • Human Health.

In addition to the topical-based chapters, there is a chapter summarizing regional key climate-related risks for the Oregon Coast, the Willamette Valley, the Cascade Range, and eastern Oregon. This chapter also highlights some recent regional case studies.   

Chapter 2 provides an Overview of Climate Change in Oregon - primarily regarding shifts in temperature and precipitation, along with focal impacts of extreme heat, extreme precipitation as well as reduced snowpack, drought and subsequent water supply issues. 

In the chapters following, impacts discussed for each sector are detailed relative to the past experience, current impact, and future projected outcomes due to climate change. Some of the impacts as described for each sector are:

Ch. 3 Water

  • Warming temperatures, changes in precipitation, and decreasing snowpack are already having significant impacts on hydrology and water resources.
  • Projected future changes in water supply and demand are expected to strain the ability of existing infrastructure and operations to meet the many and varied water needs.
  • Changes in streamflow timing and amount and warming streams are expected to degrade freshwater fish habitat.

Ch. 4 Coastal:

  • The Oregon coast is expected to face greater coastal flooding and erosion hazards with sea level rise.
  • At Newport, sea level is projected to rise by 12 to 47 inches under the high emissions pathway by the end of the 21st century.
  • Changes in the ocean environment - warmer temperatures, less oxygen, ocean acidification - are expected to result in substantial ecosystem shifts in Oregon’s coastal waters.

Ch. 5 Forest Ecosystems:

  • Changing climatic suitability and forest disturbances from wildfires, insects, diseases, and drought will drive changes to the forest landscape in the future.
  • Conifer forests west of the Cascade Range may shift to mixed forests and subalpine forests would likely contract.
  • More frequent drought conditions will likely increase forest susceptibility to other disturbance agents such as wildfires and insect outbreaks.

Ch. 6 Agriculture:

  • Over the next decade or two, warming winters, expanding growing seasons, and carbon dioxide enrichment may boost yields for some Oregon crops and create opportunities to grow new crops and varieties.
  • Over the long term, increased heat and drought stress, water shortage, and pressure from pests and diseases may supersede the positive benefits of increased crop yield.

Ch. 7 Human Health:

  • More frequent wildfires and poor air quality are expected to increase respiratory illnesses.
  • Warmer temperatures and extreme precipitation are expected to increase the risk of exposure to some vector- and waterborne diseases
  • Certain populations, including the elderly, the young, pregnant women, the poor, persons with chronic medical conditions, persons with disabilities, outdoor workers, immigrants and limited English proficiency groups, and Indigenous peoples will be disproportionately affected by such climate-related health impacts.




Publication Date: January 2017

Authors or Affiliated Users:

  • Meghan M. Dalton
  • Kathie D. Dello
  • Linnia Hawkins
  • Philip W. Mote
  • David E. Rupp

Related Organizations:


Resource Category:

Resource Types:

  • Assessment

States Affected:


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