It’s that time of year again. Fire season is here: Red flag warnings have started waving in Arizona, New Mexico, and Colorado. Scientists are frantically measuring drought conditions as land managers are evaluating fuel loads. People are bracing for heat, flames, evacuations, and smoke.
Wildfire season is getting worse—and will continue to do so, as the climate changes—but was last year’s horrific fire season the new norm? Not necessarily, climate scientist Daniel Swain said.
2020’s wildfire season was an anomaly, even by the standards of the last five years. Four out of the five largest fires in California history happened in 2020. The biggest was the August Complex Fire, which became the first ever “gigafire” after burning more than 1 million acres. Though intense, last year was part of a growing trend: Before 2020, the biggest fire in California happened in 2018 (and before that, 2017).
Though fire is a natural part of the Western ecosystems, a combination of climate change, decades-long fire suppression, and development in forested areas have made recent fire seasons more intense and more destructive.
Throughout the fall of 2020, people in the West weathered orange skies and smoke. Dozens of people died from the fires, and Stanford researchers estimate that up to 3,000 deaths could have been caused by inhaling wildfire smoke. 2021’s fire season, scientists hope, won’t be as destructive.
What Do We Know About Fire Season At This Point?
What makes wildfire so devastating starts with preconditions (drought, high temperatures, or anything that makes the land more likely to burn). The rest is rather unpredictable: will lightning strike or campfires spark when there are high winds? The chances of big fires are getting larger as the climate changes, but it's still hard to predict the outcomes of any individual year. This year, though, looks bad.
The Western U.S. is very dry. The drought map from the National Drought Mitigation Center of the West is a patchwork of severe, extreme, and exceptional drought. The Southwest is weathering a decades-long drought, and California is facing crippling heatwaves. Last month, California Governor Gavin Newsom extended his drought emergency to 41 of the state’s 58 counties. Communities are preparing for mandatory water restrictions.
State and federal firefighting agencies are scrambling to recruit and retain enough firefighters, and some positions remain unfilled. Some cities, like those in the Bay Area, are implementing new evacuation systems to make it easier to alert and evacuate residents during a wildfire.
In California, winter is historically the rainy season. This year, though, it barely rained all year. The severity of this drought is already starting to eclipse the state’s last drought, Swain said, which ended only two years ago. All that heat and no rain means that the vegetation is dry and ready to burn.
“Looking at the predictable elements, this year is significantly worse, especially in California,” Swain said. “Whether that translates to a fire season that is worse—by whatever metric of worse we’re using—is a different question.”
A significant amount of unpredictable events need to happen for fires to burn like they did last year. For starters, you need ignitions. In 2020, a huge lightning storm in the Bay Area ignited the massive August Complex Fire. One massive fire was sparked by a gender reveal party. Throughout last year’s fire season, ignitions hit during high winds, which carried the flames throughout the state.
Large wind events played an outsized role in the historic fires in Oregon and Washington last year, too. Cliff Mass, a meteorologist who specializes in weather prediction at the University of Washington, said that while he absolutely expects fires to burn in the region—especially in the drier eastern parts of the states—he doesn’t think it’ll reach last year’s level. Just this weekend, the Pacific Northwest got a big burst of rain.
“Last year we had a lot of big grass fires because there were a lot of large winds,” Mass said. “This year, there’s no reason to expect it to be any bigger than normal.”
Lightning and wind are natural features of fire season, but there’s no way to know if they’ll return with equal intensity this year. Swain said that, at this point, he predicts that less acreage will burn in California than last year—which isn’t saying much, given the record-breaking 4 million acreage burned in 2020.
A small silver lining is that, because this year has been so dry, a lot of places haven’t had new vegetation growing. Fires will still tear through the forests, Mass said, but that could help reduce fuels for grassland fires.
What Can We Learn From Past Fire Seasons?
Part of preparing for fire season comes from studying and understanding previous fire seasons—a task that scientists are still undertaking.
And the intensity of recent fires are challenging everything we know about wildfires. Christy Brigham, the Chief of Resources Management and Science at Sequoia and Kings Canyon National Parks, was the lead author on a study that found that a single fire last year killed between 7,500 and 10,000 giant sequoias—10 to 14 percent of the mature giant sequoias on the planet.
Sequoias are among the most resilient trees to fire: Mature trees survive blazes and rely on fire to open their cones. Brigham said that prioritizing low-severity fires through prescribed burning is critical, but the window for doing prescribed burns is smaller and smaller as the West gets hotter and drier. It’s simply not safe to set fires during much of the year, anymore, when a strong wind could carry them far and wide.
Understanding how the landscape of fire is changing is critical to planning how and where to rebuild, said Karen Chapple, the director for the UC Berkeley Center for Community Innovation. She said that, as of now, most communities affected by wildfires rebuild exactly as they were before. That isn’t resilience, she said. Though rebuilding serves residents in the short-term, it puts homes right back in harm’s way of future wildfires. Chapple and her team released a recent report which looks at how communities could rebuild in the future: They could stay where they are, evacuate high-risk zones permanently, or create what she calls “resilience nodes” where people gather in cities or high density areas away from high risk fire regions.
“We’re still learning what fire season looks like under the climate change scenario that we’re living through,” Chapple said. “We can’t predict exactly what it will look like, but we can start preparing.”
For a long time, the West has focused on fighting fires rather than land management or housing policies that could reduce fire risk in the first place.
“Fire is not the enemy or even the problem. It's the high intensity fires that are clearly problematic,” Swain said. “The question is, can we decouple those fires from the catastrophes we’re seeing.”