“I think that for decades … fire practitioners have been raising the alarm of: fires are getting bigger, they’re getting more extreme. It was sort of an ongoing debate for a while. It is a century of fire exclusion, which is essentially a policy that the US adopted back in 1910 to put out all wildfires. It was called the 10 a.m. rule,” Stavros told hosts Eugene Puryear and Sean Blackmon.The rule required fires in a given area to be put out by 10 a.m. the morning after they were found.
“So, it was this idea to completely remove wildfire from the landscape. And then in the ‘70s, practitioners, ecologists and fire management experts were saying fire is a natural part of these ecosystems, and we need to allow it to happen, because we are seeing a lot of fuel accumulation,” she explained.
“And then for several decades, there was some debate. Are these extreme fires that we are seeing … is it the fuel that has been accumulated from not allowing fire, or is it because the climate is changing? My actual dissertation for my PhD that started in 2010 was to investigate the role of climate in extreme fire events explicitly. The climate changing really does play a really significant role,” Stavros added.
Earlier this week, California Governor Gavin Newsom declared a state of emergency in the Sonoma County wine region after a fire spread across more than 10,000 hectares. Newsom said that evacuations were underway and urged people to follow the directions of the authorities. Meteorologists have predicted that hot winds will intensify on Saturday and last through Monday in the San Francisco Bay area. Wildfires were also registered over the border in Mexico's Baja California state, Sputnik reported.
“Imagine that there is a spectrum, and at one end of the spectrum there’s what we call a fuel-limited system - that would be something like what you would see in Utah or Nevada. And that’s where it’s very hot and very dry - two of the ingredients for wildfire - but there is no fuel. It is very, very dry,” Stavros said. “And now the fuel is very sparse. Now, we can see fuel - especially if there’s been a big rainstorm one year and a bunch of grass grows - and the next year, we’ll see big fire events. That’s what we see in a fuel-limited system.”
“On the other end of the spectrum, you have a flammability-limited system, and a flammability-limited system is one kind of like the Olympic Peninsula in Washington state or what you see in the Southeast,” she explained. “It’s very moist and typically cooler - so not really a place you would expect to have a lot of fires, but you have a lot of fuel. Those areas can experience drought, and so that's when you'll see more fires there.”
“As the climate’s changing, ecosystems are sort of moving along the spectrum, and systems that may have had a lot of fuel before are getting dried out, and then once a fire comes, it has this very interesting effect where it can create a clean slate, and what comes back on the landscape, especially if its getting hotter or dryer, may not be what was there before. And so a system that may have been one kind of fire regime may shift and become another kind of fire regime,” Stavros added.
According to Stavros, recent research suggests that areas with aggressive development are more likely to experience wildfires.
“As we build, we actually increase the likelihood of a fire event. A recent study by a woman out of University of Colorado Boulder showed that areas where we’ve grown into a wildland is where we have increased likelihood of an ignition event and that can come from things - the most common one I hear people say is cigarette butts - but it could just be … something hanging off of your car and it created a spark.”
“And that’s where you start to hear things about Red Flag Warnings, and that’s what we’re saying across the state of California today. On the other hand, there’s where do we actually build, and where we actually build is sort of an area of ongoing research,” she explained, also noting that the likelihood of fire is also based on “topography, how weather and climate moves across the topography, proximity to infrastructure and the type of fuel that’s there.”
The US National Weather Service defines a Red Flag Warning as applying when “warm temperatures, very low humidities, and stronger winds are expected to combine to produce an increased risk of fire danger.”
Air quality is also affected by wildfires, although clean air is something we often take for granted, Stavros pointed out.
“Wildfire events can reduce air quality thousands of miles away. So, fires in Canada can affect air quality in Florida … downwind effects of degraded air quality from wildfires can include things like increased asthma attacks, increased heart attacks, increased infant fatalities.”
Many of the existing technologies used to prevent wildfires are extremely costly, Stavros also explained.
“Some of the things that we could actually do are things like downed powerline detection. So there are technologies we can put on powerlines … It could be things like burying power lines. Now, that’s extremely expensive,” Stavros said.
“There are other proactive approaches that can be taken, like managing the fuels that we have. Another way, and this seems counterintuitive, [is] prescribed fire. So that is bringing in all of the scientific data we have to understand when is the likelihood that this fire is going to get out of control. Let’s not burn on those days, but let’s burn on the days that we think we can control it the most,” Stavros explained.
According to the National Park Service, when officials set prescribed fires, a “scientific prescription for each fire, prepared in advance, describes its objectives, fuels, size, the precise environmental conditions under which it will burn, and conditions under which it may be suppressed.”