In the not-too-distant future, Oregon will face summer water shortages, an increase in wildfire risk and more extreme weather events, according to the first Oregon Climate Assessment Report released this week.
Such developments will bring new environmental responses to climate change and many economic challenges – and opportunities, says the report.
Written by some 70 authors from universities, state and federal agencies and other groups, the report was produced by the Oregon Climate Change Research Institute, an Oregon University System entity housed at Oregon State University.
The legislatively mandated report is available at www.occri.net/ocar
“Oregon faces some significant challenges because of a changing climate and this report synthesizes some of the best available science to gain a glimpse of our future,” said Philip W. Mote, a professor of oceanic and atmospheric sciences at Oregon State who directs OCCRI.
“Having said that, there are some clear gaps in our research knowledge that must be addressed – especially the economic impacts of climate change – if we are to help communities, businesses and organizations better prepare for the future.”
Kathie Dello, a research associate with the Oregon Climate Change Research Institute, coordinated production of the report with the help of nine lead authors and peer-review panels.
The report examines the potential social, physical and biological responses to an Oregon climate that may increase in average temperature from 0.2 to 1.0 degrees Fahrenheit per decade through the 21st century, the authors note. A key variable to these and other changes are global greenhouse gas emissions that will influence Oregon’s future climate.
“The key ‘drivers’ of emissions are population, consumption and the emission intensity of the economy,” Dello said.
Oregon’s supply of fresh water may be one of the most critical components of climate change. A compilation of different climate models suggests that the state’s average summer precipitation will decline by about 14 percent by the year 2080, but the impacts will vary over time and space, said Heejun Chang, a Portland State University geographer and hydrologist who led the section on freshwater resources.
“In terms of water supply, some lower Willamette River sub-basins – including the Tualatin, Clackamas and Molalla rivers, where population is growing – are more vulnerable to climate change,” Chang pointed out. “And with reduced summer precipitation, summer flow is projected to decline in the western Cascade regions, which in turn will increase stream temperatures and further stress cold-water fish species.
“The warming by itself makes both floods and droughts likely to occur more frequently in the future,” Chang added. “If you couple hydroclimate and transportation models, it shows that winter floods might occur more frequently, which may damage regional transportation systems in urban areas and landslide-prone areas.”
The Oregon Climate Assessment Report is partly modeled on similar reports produced in Washington and California, but covers new ground, including greater emphasis on the marine environment, on fish and wildlife, and on human dimensions, Mote said.
Increases in ocean temperatures and acidification likely will further disrupt marine ecosystems and could lead to more near-shore hypoxia and so-called “dead zones,” harmful algal blooms, invasive species, and challenges for shellfish and other sea creatures, the report concluded. Oregon’s coastal region also will be subjected to more intense storms and higher waves, creating a greater risk of flooding.
“One unique aspect of this report is the contribution by OSU oceanographers who have led near-shore studies for more than 40 years that have resulted in a remarkably well-sampled coastal region,” Mote said. “There are few places in the world that have such a rich database on coastal oceans.”
Other conclusions in the report:
-- The global mean sea level is expected to rise an estimated one meter by the year 2100, but the rate of sea level rise will surpass the vertical land movement taking place through geological processes along the Oregon coast by the mid-21st century;
-- Also by the mid-21st century, Cascade snowpacks are projected to be less than half of what they were in the 20th century, with lower-elevation snowpacks most vulnerable;
-- Irrigation demands will increase as the climate warms, the authors say. However, warmer weather may create extended growing seasons and greater yields for some crops and opportunities for new crops or varietals;
-- Drawing on research from the University of Washington, the authors say that wildfire is projected to increase in all forest types in the coming decades because of warmer, drier summers and an increase in fuel. “Large fires could become more common in western Oregon forests,” the report concludes.
-- The authors say the largest data gap facing Oregon decision-makers is economic research. Some preliminary studies, based on individual sectors such as Oregon’s ski industry, have been started, Mote said, but large-scale “macro-economics” research is lacking.
“We know that Oregon’s low-elevation ski resorts will be affected first by changes in precipitation,” Mote said, “and economists could quantify how much they will lose with each week of a shorter ski season. What is missing is detailed analysis of the pros and cons of climate change for the whole of Oregon. If we manufacture fewer parkas, do we make more swimsuits? As we lose some crops, do we grow others?
“Oregon also needs a more detailed look at its infrastructure needs,” he added. “If we have more coastal flooding, for example, how many communities have adequate water and sewage treatment facilities? Adequate road systems? Those are the kinds of questions that need to be asked next.”
The report includes lead and contributing authors from OSU, PSU, University of Oregon, the U.S. Forest Service, the U.S. Geological Survey, Oregon Department of Fish and Wildlife, Oregon Department of Agriculture and others.