Oregon Wildfires: Is Climate Change the Culprit?

In Oregon, we have watched California experience devastating wildfires year after year. This summer, we watched our own state burn. Many Oregonians lost their homes, neighborhoods, and lives as multiple, formidable fires overtook the state.   

The question on everyone’s mind is why? And more importantly, how do we stop it from happening again?   

Director of the Oregon Climate Change Research Institute and professor at OSU’s College of Earth, Ocean, and Atmospheric Science Erica Fleishman says that climate change is partially to blame.  

“Climate change is one of the factors that is increasing the number, size, and severity of wildfires,” Fleishman said. “In Oregon, the largest wildfires historically have occurred in relatively warm, dry summers, and such summers are becoming more frequent.  

In August 2020, most of the Pacific Northwest experienced below-normal precipitation and above average temperatures – the perfect, devastating formula for wildfires.   

Generally, the average annual temperatures have increased by two degrees Fahrenheit since the beginning of the 20th century. Oregon is projected to warm by four to nine degrees Fahrenheit by the year 2100, depending on how we deal with global emissions.   

Change in Climate Leads to Drought 

 Fleishman explained that with less precipitation, plants become dry and can carry fire more readily  

“Drought is a function not only of total precipitation, but of temperature and of the timing and type of precipitation,” she said. “For example, spring snowpack is declining throughout Oregon, especially at lower elevations. Vegetation becomes dry more quickly than in the past, prolonging the fire season and the probability that when a fire ignites, it will become large, and will do so rapidly.” 

 Since the U.S. Drought Monitor started in 2000, Oregon’s longest drought lasted from December 2011 to February 2017. Currently, 8.7% of the state is considered abnormally dry, 19.3% is experiencing a moderate drought, 31.9% is experiencing a severe drought, and 33.6% is experiencing an extreme drought.   

Settlements & Cheatgrass  

Fleishman explained that wildfires across the western United States reflect long-term climate change interacting with other factors, including shorter-term weather patterns, and both long-term and short-term patterns of human settlement and other activities.   

“Long-term climate change in the western United States affects wildfires in large part via drought, which increases fuel loads,” she said. “In the high deserts of eastern California, Oregon, and other western states, wet winters, which are projected to become more common as climate continues to change, often are associated with an increase in abundance of cheatgrass.”  

Cheatgrass, Fleishman explained, is a non-native invasive grass that is highly flammable and expands quickly after fires and other ground disturbances. As this grass expands, it helps increase the frequency and extent of fires.   

“Short-term weather patterns, especially heat and wind, also affect the size and intensity of wildfires,” Fleishman said. “Many of the largest fires in Oregon and California in recent years coincided with high winds that allowed fire to spread rapidly and contributed to conditions in which fires were extremely difficult to contain.”   

Another factor contributing to wildfires is where people are building their homes.   

“Over the past several decades, an increasing number of people have built homes in areas often referenced as the wildland-urban interface – essentially rural areas in which the likelihood of fire is fairly high,” Fleishman said.  

Over the last few decades in the western United States, human activity, as opposed to lightning, ignited more than 60% of wildfires, whether caused by powerlines, arson, debris burning, smoking, or campfires.   

“Therefore, changes in where people live, and human population density, also affect the likelihood and size of wildfires,” Fleishman said.   

Scientists, over the past couple decades, have been examining how climate change affects the probability of extreme events using a form of analysis called attribution.   

“For example, scientists can estimate the extent to which climate change increases the magnitude of a flood,” Fleishman explained. “Scientists cannot conclude with confidence that any given event was caused by climate change, but they can compare the probability of an event in the absence of observed climate change to the probability given observed changes in climate.”   

The Wildfires Weren’t a Surprise  

Using attribution for wildfires is more complicated, because wildfires have many drivers. However, what the western United States is experiencing in terms of wildfires is something climate scientists and other researchers have been projecting for decades, according to Fleishman.   

Despite the considerable amount of research and data that shows climate change is somehow contributing to wildfires, some are quick to refute its role in these natural disasters. Fleishman said that public resistance toward scientific evidence appears in other issues as well, such as ways to reduce the transmission of COVID.  

Fleishman cited a study conducted by the Yale Project on Climate Change, which classified attitudes toward climate change on a six-level gradient, ranging from alarmed to dismissive. Researchers ultimately found that values, political ideology, and religious beliefs correlated considerably with attitudes about climate change.   

“Resistance to the scientific evidence on climate change tended to be associated with opposition to government intervention and the belief that environmental protection and economic growth are incompatible,” Fleishman said.   

However, if the public doesn’t take climate change seriously soon, the effects could be detrimental. In the instance of wildfires, they could become more intense and frequent.   

How to Combat Wildfires  

To combat climate change right here in Corvallis, Fleishman stressed two important courses of action: voting and being conscious of your choices.   

“First if they have the right to vote, they can vote. Comprehensive efforts to reduce emissions of greenhouse gases that cause climate change requires action at local, state, national, and international levels,” Fleishman said. “Therefore, the actions of elected officials affect the magnitude of climate change. Individuals also can communicate with their legislators about their priorities.  

“Second, individuals can make choices about their resource-consumption behaviors and about family planning. Through their daily purchases and longer-term investments, individuals also can support businesses that develop or adopt technologies that minimize emissions of greenhouse gases.”   

Fleishman also suggests supporting policies that create greater climate equity, as economically disadvantaged and marginalized communities suffer disproportionately from the effects of climate change.  

Despite climate change being a large, overwhelming issue, how we vote and the everyday choices we make ultimately have the ability to make a positive difference.   

“The overwhelming weight of scientific evidence indicates that climate change is real, is happening now, and largely is caused by human activity. Society can mitigate the extent of climate change, and society can take action to adapt to the inevitable effects of climate change,” Fleishman said. “Both types of actions will be needed to minimize undesirable effects on natural and human systems, and the cumulative effects of many individual behaviors can make a tangible, positive difference.”  

By Cara Nixon