Ask Eartha: Are there any connections between wildfires and climate change?
With two wildfires in Summit this past week, several more burning across the state and a June that was drier than average, are there any connections between wildfires and climate change?
Thanks for your question this week, Liz. It’s an important topic, because wildfire is one aspect of climate change that we don’t consider often enough, especially since it’s not every day a wildfire flares up in your backyard. From the Steward household in Dillon, we watched the smoke billow high into the sky as the Peak 2 fire climbed uphill. Now a week later, the fire is almost completely contained, the rains have begun, and all that’s visible is a scorched scar on the hillside. We’re very fortunate to have excellent firefighting resources locally and to have the support of neighboring communities as well as federal agencies. Firefighting isn’t easy work, and we’re grateful to the folks who’ve made it their profession.
So is there a link between wildfires and climate change? The short answer is yes. And while climate change didn’t start the Peak 2 fire, it contributed to conditions that allowed this fire — and many others currently blazing across the American West — to burn. Here are a few ways that climate change influences wildfires:
The average fire season in the American West is now 105 days longer than in the 1970s. Forests are considered combustible roughly a month after snows finish melting. With rising temperatures leading to earlier onset of spring and warmer falls, the fire season is extended.
Warm air holds more moisture than dry air. As temperatures rise, the air sucks more moisture out of the soil, trees, plants and dead vegetation. Drier fuels ignite more easily, turning forests into tinderboxes.
Scientists predict that for every degree of warming, the number of lightning strikes will increase 12 percent. Lightning only causes about 15 percent of the wildland fires ignited in the U.S. each year, but lightning-caused fires burn more acreage than human-caused fires do.
And Bark Beetle Outbreaks?
While it might seem logical that stands of dead trees might increase wildfire risk, research actually contradicts this idea. Climate change drives both bark beetle outbreaks and wildfires, but there is no connection between beetle outbreaks and the frequency or size of fires. And recent beetle outbreaks only increase the severity of fires under the most extreme conditions (low humidity, high temperatures, high winds). The primary drivers for fire severity are burning conditions and topography.
To put this all into context, let’s consider some local data:
• In Colorado, average temperatures have increased two degrees since the 1970s.
• In Colorado, the average year in the 2010s saw 30 times more acres burned by large wildfires as the average year in the 1970s.
• Nine of the 10 largest fires in Colorado’s recorded history have occurred since 2002.
• Two million people live within the 6.6 million acres of Colorado’s wildland-urban interface, places where man-made structures are built close to natural terrain with a high potential for wildland fire. In Summit County, 99 percent of us live within the WUI.
It’s important to remember that forest fires aren’t inherently bad. Quite the opposite, in fact. As noted by Thomas Swetnam (a tree ring expert from the University of Arizona), “Most land plants are well-adapted to fire at some frequency and intensity, and some even require fire to grow and regenerate. The negative impacts of wildfires now, however, derive from a wicked combination of changes in ecosystems, increasing numbers of people building their homes in fire-prone places, and increasing temperatures and drought.”
This is the reality we’re living in: As average temperatures rise, so do the frequency and intensity of wildfires. And while you might not be the type of person moved by photos of starving polar bears or rising seas in Florida, will the increased risk of natural disaster in your own backyard inspire you to take action?
What can you do? Create defensible space around your home, to start. Use the Summit County Chipping Program to remove woody vegetation from around your home — you stack it, the county hauls it. But think big picture, too. We’re stuck with some degree of warming, but we don’t have to let the temperature increases run away from us. Decrease your carbon footprint and encourage your friends and family to do the same. Take HC3’s pledge to reduce your energy use by 10 percent this year, and get an energy audit to help you figure out how to make your home more efficient. Use public transportation as much as you can. Support efforts to bring 100 percent renewable electricity to our local communities and our state. Grow your own food and support water conservation methods. If we can work together to limit the amount of warming caused by climate change, we can lessen the wildfire risk we all face.
Ask Eartha Steward is written by the staff at the High Country Conservation Center, a nonprofit dedicated to waste reduction and resource conservation. Submit questions to Eartha at firstname.lastname@example.org.
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