How might climate change affect Oregon?

Lewis and Clark Trail

Oregon is a beautiful coastal state located in the northwestern region of the United States with four distinct seasons: fall, winter, spring, and summer. The Cascade Mountains run down the western side of the state and split it into two different climates. Along the west of the mountains, near the ocean, the climate is very wet and in some parts, subtropical. On the eastern side of the mountains the climate is more arid and dry.

Several changes in climate are predicted for Oregon in the coming years, including further warming trends (increases of about 0.2 to 1 degree F per decade) and drier summers. The United States Historical Climatology Network has been collecting temperature data throughout Oregon for several decades, and recent data indicate an increase in average yearly temperatures at all of their weather stations. Information about average yearly precipitation is more variable and trends are still unclear.

Further changes to Oregon's climate in coming decades may include: an increase in the length of growing seasons, an increasing number of frost-free days, and a decrease in snowpacks in the Cascades to half of current levels by mid-century. Warmer temperatures, in combination with decreased snowpacks, may lead to peak flows earlier in the year and water shortages later in the season. Agriculture will have to adapt to decreased availability of and increased demand for water resources and farmers will need to adjust their crops with changing growing conditions. New agricultural pests and diseases can also be expected to move into Oregon.

Along Oregon's coast, sea levels are likely to rise, lowering beach elevations and causing problems for waterfront property owners. Coastal flooding will probably increase due to more intense storms. Rising air temperatures will lead to increases in ocean temperatures. Changing ocean temperatures will lead to lower dissolved oxygen levels and an altered environment for marine organisms. Oregon is already seeing species from warmer, southern regions move north into Oregon coastal waters.

What does this mean for the Lewis and Clark National Historical Park?

Elk at Lewis and Clark

The Lewis and Clark National Historical Park is located along the northwest coast of Oregon and even includes sites up into Washington state. The park's elevation ranges from sea level to 300 ft atop Clatsop Ridge. Changing climatic conditions as described above may bring with them sea level rise and coastal flooding due to more intense storms. These conditions may create some challenging management conditions for the Lewis and Clark National Historical Park as the park staff manages both the ecological systems and the historical artifacts in the park.

Unique questions can also be asked at the Park in part because of the historical aspect of this park. During the winter of 1805-06, Meriwether Lewis and William Clark recorded their observations of the plants and animals they saw while staying at Fort Clatsop, which is now part of Lewis and Clark National Historical Park. Some of the plants they recorded that winter were new to science and had never before been described, including Evergreen huckleberry and salal. Both of these species are included in the Top 10 for this park. How has the vegetation changed since Lewis and Clark's visit? How will the vegetation change in the park in the future with changing climatic conditions? You can help answer these questions by recording observations of the timing of phenophases for plants like salal and Sitka spruce. Your observations will also provide a better understanding of how these important species to the park might be affected by changing climatic conditions.

"Project Budburst is a wonderful way to carry on the tradition of scientific observation & discovery handed down to us by America's first great naturalists, Lewis and Clark. It is exciting that we will be observing the same plants they recorded for the first time here over 200 years ago in their elk skin journals, but we will be using Smartphones and the internet. So much has changed over the last two centuries, but the importance of detailed observation and record-keeping for the advancement of science and our understanding of the world around us remains the same."

-Carla Cole, Natural Resources Program Manager


Photos: Courtesy of Lewis and Clark National Historical Park

Oregon Climate Change Research Institute. 2010. Oregon Climate Assessment Report, K.D. Dello and P.W. Mote (eds). College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR.

National Park Service. Lewis and Clark National Historical Park website. Nature and Science page. Accessed 20 Sept 2012.