'A Little Bit Of Warming And A Lot More Burning': How Climate Change Is Impacting Wildfires
According to a list compiled by The Denver Post, the state’s top 10 largest wildfires have all taken place in the past 20 years. And the Pine Gulch Fire burning north of Grand Junction is on track to eclipse the 2002 Hayman Fire as the largest in our state’s history.
So why is our state seeing all of these record-breaking fires?
KUNC’s Colorado Edition reached out to Jennifer Balch, a fire scientist and director of Earth Lab at the University of Colorado Boulder, to help answer that question.
These interview highlights have been lightly edited for length and clarity.
Matt Bloom: Why is our state seeing more record-breaking fires in the last 10 to 20 years?
Jennifer Balch: We’re definitely seeing the impacts of climate change across the West. In fact, our fuels are drier as a function of increasing temperatures, and that’s leading to a lot more burning. In fact, it just takes a little bit of warming for fires to respond really significantly. And so we’re seeing a little bit of warming and a lot more burning.
And across the West we’ve seen a doubling of the amount of forests that have burned since the 1980s. And since the 1970s, we’re seeing five times more large fires than we did in that decade.
"Fire needs three things to burn: it needs a warm and dry climate, it needs fuels to burn, and it needs an ignition source. And people are effectively changing all three."
So we know warming is a major driver. How does the warming impact the size, duration and severity of these fires?
Fire needs three things to burn: it needs a warm and dry climate, it needs fuels to burn, and it needs an ignition source. And people are effectively changing all three.
So we have seen about a 2 degree Fahrenheit increase across the Western U.S. since the earlier part of this century and we’ve seen actually significant warming in the region that’s burning in western Colorado. In fact it’s actually much higher than that, and it’s twice the global average increase in temperature.
So right where we have wildfires burning right now is essentially a hotspot of climate change. So that’s one thing.
The other thing is fuels. And we change fuels, we bisect through building roads, we introduce invasive grasses, and there’s lots of ways that people change fuels and fuel structure.
And then the last piece that’s also really important is that people provide the sparks, sometimes, that can burn fires. There’s two general sources of ignitions: one is lightning and one is people. And we’re right in the middle of the lightning ignition season right now. So a lot of fires across the West are started by lightning, but we also have human-started fires in the mix.
The other thing that’s happening is when you throw climate change in the mix with human ignitions, we’re essentially creating longer fire seasons because of a warmer fall, and warmer summers that the ignitions then are more related to what people are doing than they are to lightning.
Could you help us understand how big this year’s fire season is in Colorado compared to the normal, or the average?
The four largest wildfires that are burning right now in Colorado have already burned through over 200,000 acres, and this is well above the average since 2002, which is about 80,000 acres. So we’re more than double the average that we’ve seen over the last several decades.
And the fire season is not over yet — it’s only August and half the state is in severe to extreme drought conditions right now.
"We’ve committed to a certain degree of climate change, and in order to reverse or mitigate this, we’re looking at a very long road."
Can we expect to see more record-breaking fires in Colorado over the next decade?
Yeah, I’m certainly not expecting our fires to go down in size anytime soon. We’ve committed to a certain degree of climate change, and in order to reverse or mitigate this, we’re looking at a very long road. And so the next several decades, I’m not expecting our fires to be smaller or to go out easier.
In fact, I think our firefighting community, they’re feeling the heat right now in terms of being totally stretched thin.
We’ve got firefighting communities that are fighting fires all across the West right now, and they’re exhausted. And we’re making hard decisions about resource allocation in terms of where we put fires out.
In fact, in Colorado one of the most important ones right now is Grizzly Creek, because it’s right along the Colorado River, which supplies a huge number of people and agriculture with water. So fires are important, because they essentially remove and denude landscapes, and make it easier for flooding to carry debris and particulates down to our river systems.
So, as a fire scientist, I don’t expect fire to go away anytime soon, and I think we are looking at very large fires and more record-breaking years.
This interview is from KUNC’s Colorado Edition from Aug. 26. You can hear the full episode here.