The 2020 fire season on the West Coast has been reported to be the most disastrous of this decade. Wildfires stretching along California, Oregon and Washington have already killed over two dozen people, displaced thousands of individuals along the West Coast and burned over five million acres of land.
The effects of the West Coast fires can even be seen all the way across the country. This month, smoke and haze were reported along the Eastern Seaboard. In Baltimore, a thin layer of smoke was spotted from the evening of Sept. 14 to the morning of Sept. 15, and the skies appeared to have a slight red hue.
Molly Menzel, a PhD candidate in the Department of Earth and Planetary Sciences (EPS), described how winds carried the smoke from the wildfires on the West Coast to the East Coast.
“[Baltimore] is located in the midlatitudes, between 30 and 60 degrees north. Weather in this region travels from the west to the east due to the jet stream, a large atmospheric jet with strong winds travelling to the east. This allows for aerosols like smoke to be advected, or transported, across the continent to where we are located,” she wrote in an email to The News-Letter.
Once smoke particles reach the skies of the East Coast, they scatter light in a way that causes the skies to appear red, Jacob Shultis explained in an email to The News-Letter. Like Menzel, Shultis is a PhD candidate studying EPS.
“Since smoke and ash are larger than normal air molecules, they act to scatter slightly larger wavelengths of light, leading to the reddish color that we saw [in Baltimore],” Shultis wrote.
The driving forces behind the ignition and spread of wildfires range from natural events to human activity.
Low levels of evapotranspiration, according to EPS PhD candidate Mahmoud Osman, support the initiation and development of wildfires. Evapotranspiration is the sum of evaporation from water bodies and transpiration from plants. Both evaporation and transpiration release water into the atmosphere.
“With precipitation deficit, in a water limited environment actual evapotranspiration becomes very low and plants die and leave debris that act as fuel to wildfires. Natural reasons (such as lightning) or human activities can be just a spark to set the fire to the drought hit region,” Osman said.
Benjamin Zaitchik commented on the recent, problematic trends in wildfire activity in an email to The News-Letter. Zaitchik is an EPS associate professor who researches climatic and hydrologic variability. He noted that the convergence of at least two human influences is making these fires worse: insufficient forest management and encroachment on wildlands.
According to Zaitchik, forest management is a complex issue, in part because it is heavily politicized. Some people argue that climate change is a bigger contributor to the intensity of wildfires than subpar forest management. In reality, it is a combination of both.
Prescribed fires, according to Zaitchik, is one solution. These controlled burns decrease the buildup of dry vegetation which fuels the spread of huge wildfires.
Yet, even once forests are fully managed, questions remain.
“Do we clear cut and replant forests as monocrops of fire-susceptible species, or do we pursue more integrated management strategies that preserve fire resistant species and natural ecosystem breaks?” Zaitchik wrote.
The answers to these questions are still being debated.
In addition to inadequate forest management, the construction of settlements near forests also contributes to the initiation of fires. According to Zaitchik, such settlements increase the potential of humans starting fires and also increase the human toll of each wildfire.
With reports of longer and more extreme wildfire seasons come greater concerns for fire containment. California’s Creek Fire began on Sept. 4 this year and has already burned over 300,000 acres. Despite ongoing efforts for fire containment, the Creek Fire was still only 39 percent contained as of Sept. 27. In addition to being California’s largest wildfire on record, the Creek Fire displayed unusual fire behavior, spinning up fire tornadoes with winds as strong as 125 mph.
However, according to Zaitchik, it is difficult to say if the frequency of intense, rare events such as fire tornadoes is actually increasing in a significant way.
“We have to be careful to separate actual trends from our perceived trends, based simply on how much attention we’re all paying to these fires now, and how advanced our monitoring capabilities have become,” he wrote.
The long term impacts that wildfires will have on the global climate are still difficult to discern and are still subjects of scientific research.
“The intense release of smoke into the atmosphere, as is being done by these wildfires, may have drastically complex impacts on the climate system,” Menzel wrote. “Many scientists are still trying to discern those impacts.”
Although scientists are still studying the long-term impacts of longer and more extreme wildfire seasons, Zaitchik noted that the wildfires will certainly affect the viability of certain ecosystems in the fire-affected region.
Forests are considered “carbon sinks” when they absorb more carbon than they release and “carbon sources” when they emit more carbon than they absorb. Zaitchik explained that longer and more extreme fire seasons may threaten the natural and environmentally beneficial function of forests as “carbon sinks.”
“We get a big free ecological service from trees taking up carbon dioxide, but it’s not a given that the strength of that free carbon sink will stay the same when human-induced warming leads to these kinds of ecological change,” he wrote.
With a more optimistic outlook on the wildfires, Zaitchik believes it is an opportunity for change. The wildfires may influence the adoption of more environmentally-friendly measures, such as better forest management and the discouragement of construction in high wildfire-risk areas.
“If fires make us think more carefully about how and where we build and how we interact with wild forest ecosystems, then there’s the potential for more ecologically friendly development,” Zaitchik wrote. “It’s also possible the severity of these fires will motivate action on climate change, which is the overarching challenge of our times.”