The Cascading Disasters of Wildfire Season

Published Sep 22, 2020

Climate scientist and Bay Area resident Dr. Kristy Dahl discusses how global warming is fueling wildfire season and its impacts on the most vulnerable.

In this episode
  • Colleen and Kristy talk about the recent wildfires in the US
  • We take a look at how this affects air quality, and families under lockdown
  • Colleen asks how to respond to those skeptical about climate change's role in the fires
  • Kristy breaks down the science behind it
Timing and cues

Opener (0:00-0:32)
Intro (0:32-2:18)
Interview part 1(2:18-12:07)
Break (12:07-12:59)
Interview part 2 (12:59-21:31)
Segment throw (21:31-22:42)
Ending segment (22:42-27:33)
Outro (27:33-28:30)

Related content
Show credits

Ending segment: Katy Love
Editing: Omari Spears
Additional editing and music: Brian Middleton
Research and writing: Jiayu Liang and Pamela Worth
Executive producer: Rich Hayes Host: Colleen MacDonald

Full transcript

Colleen: Kristy, welcome back to the podcast.

Kristy: Thanks so much, Colleen, it's a pleasure to be with you.

Colleen: Yeah. I think this is actually your third time on the podcast.

Kristy: I think that's right and I think it may be my first talking about wildfires though.

Colleen: Let's start a little bit...because you're in the Bay Area. Can you tell me what it's been like these past few weeks and kind of what you're seeing on the ground?

Kristy: I live in San Francisco. So, there's no immediate threat to the city, of fire, but for the past few weeks, we have been dealing with very poor air quality due to smoke from wildfires around the state. So right now, there are more than 3 million acres that have burned across California, Oregon, and Washington. So that's an area that's just slightly smaller than the state of Connecticut. It's the most extensive fire season on record. And we, in the Bay Area, have been feeling it in terms of our air quality.

And just for perspective, a healthy air-quality index is something below 50. Where we are this morning is above 200. So we're in a category of air that's unhealthy for just about everybody. And that air-quality index will dictate, you know, what my family and I do on a given day. It dictates whether my kids join me for walking the dog or whether they can step into the backyard during recess for school since they're at home schooling right now.

There's a real sense of confinement, here in the Bay Area, and a real sense of the gravity of the fires this year. And it's not just this year, I mean this is, you know, the third or fourth year in a row where we've had really extensive, really disruptive, and terrifying wildfires in the States. So I think people are feeling really sad and grieving for the California that we've known for so long.

Colleen: So Kristy, people who are out there that don't have places that they can go where they can turn on an air purifier. It seems like a really big health risk for so many people.

Kristy: Absolutely. I mean there're the immediate people who are affected by fires and need to evacuate their homes and have nowhere to go. There are people whose homes have been completely destroyed. There are people who are suffering through power outages related to the fires so that, even though they can be in their homes and they're not in danger, you know, they can't be running air purifiers. And then, there are people whose jobs require them to work outside. And that's perhaps the most heartbreaking of all because, you know, these are people like agricultural workers who are so invisible in our food system and yet are so critical to, you know, really the entire country having food to put on their plates. So, in the midst of this really choking thick smoke, they're out there harvesting the almonds and lettuce and tomatoes that are feeding the entire nation.

Colleen: Are they provided with any sort of protection?

Kristy: You know, there are some regulations in the state about exposure to wildfire for outdoor workers, just as there are for extreme heat. The reality is that the safest thing to do when it's this smoky is to stay indoors. And many workers may not feel that that's an option. Typically agricultural workers are very low-paid workers, many of them are immigrants, many of them are undocumented. And so, there's a real fear of not working during this time, both because, you know, they need the income and, you know, there's fear of retribution on the part of their employers if they take time off.

And so, really the only protection that we have is face masks, which, as we know, are in short supply right now. Because the kind that you need to protect yourself from wildfire smoke is an N95 mask, and that's the same kind of masks that our healthcare workers need to protect themselves from the coronavirus right now. So they're in short supply.

Colleen: A friend of mine posted a photograph of the air quality, and it was very orangey and very surreal-looking. And she mentioned in her post climate change and the connection of wildfires to climate change. And somebody responded, "Oh, that fire was caused by a lightning strike," and then, I thought, "Well, I wonder what Kristy would say." How do you respond to something like that when people aren't making the connection at all?

Kristy: Yeah. It's a bit of a challenge, right? Because wildfires are a natural part of our climate system and our ecosystems out here in the west. Fire is actually a really important part of the ecosystem. Trees like redwoods have evolved to have this incredibly thick fire-resistant bark. And the heat from wildfires allows seeds to disperse in our forests and to allow our forests to rejuvenate themselves.

So one could say the same of something like hurricanes, for example, hurricanes are a natural part of our climate system. But climate change is one very key factor among several that's pushing fires to new extremes. So, if we take a look at how that works, fires need fuel and for wildfires that fuel comes in the form of dry vegetation. As our climate has warmed, it's become easier and easier to dry out that vegetation, just like it would be easier to dry out a fresh apricot if you put it in the oven.

Recent studies have shown that human-caused climate change is responsible for about half of the drying we've experienced in the western U.S. since the 70s. And it's responsible for roughly a doubling in the number of acres burned since the mid 80s. So the conditions that we're seeing today, this record-breaking heat across the globe, record-breaking fires across the west, have really been decades in the making. And that means that when we have a really incredible lightning storm, like we did back in mid-August, the landscape is primed and ready to burn. So it's not just a lightning strike, it's a lightning strike that happens after decades of drying in California and having these really intensely hot and dry conditions.

Colleen: So, what is typically the start of the wildfire season?

Kristy: So, we typically start to see wildfires burning in the summer. And typically the season ends sometime in November when we start to see our first rains. So, the west has, rather than your typical four seasons you might see in a place like New England, we have a wet season and a dry season. So it's pretty typical in the west for it not to rain between about mid-April and mid-November, just not a drop of rain. And it's really not until we start to get those rains in the wintertime that we see an end to the fire season.

But in recent years, it's hard to even say when the fire season is because we're starting to see fires burning all year round. And what we have known about fires is changing so quickly.

For example, firefighters often talk about how much more quickly fires are spreading in the current climate because our nights are getting warmer. And, as opposed to having conditions like in the past where it would cool off at night, maybe you'd see some dew accumulating, get some dampness in the evening that would tamp down on the wildfires' growth at nighttime, now we're seeing explosive growth through the night. So that's really pushing our firefighting capabilities to their limits.

Colleen: How is this season shaping up in comparison to previous seasons?

Kristy: So, this season of wildfires has been record-breaking, not just in California but in Oregon and Washington as well. For some perspective on that, the largest fire in recorded history for California is currently burning. It's called "the August complex fire." And it currently is about 750,000 acres, just enormous. The second biggest fire was only about 450,000 acres, so we're talking a fire that is more than 300,000 acres larger than the last record setting fire in size. So these fires are burning, they're incredibly large. And because of that, it's difficult to get them under control and they will likely be burning for quite a while.

Colleen: And these two fires, this is the largest and the second largest and they're burning now?

Kristy: Of the top five largest wildfires in recorded history, in California, three of them are burning right now. So the first, third, and fourth in that top-five list are all burning now. And actually all five in that top-five list have burned since December of 2017. So we see the records broken again and again.

[Break]

Colleen: I was reading an article in "The New York Times" that described what is happening as sort of a domino effect. And that many of the consequences are things that we don't readily think about with wildfires. Can you talk about some of these other consequences that might not be top of mind?

Kristy: Yes, and I think there are many. You know, one of the first ones that comes to mind is the impact that burn scars have on our landscape. So, a burn scar is the burned land surface that's left behind by a wildfire. So, obviously, they're forming in the dry season when we have the wildfires most. But as we head into the wet season later on this fall and this winter, those burn scars present a really large risk for flash flooding and something called debris flows, which are basically floods where a whole bunch of sediment and rock comes along with it. So, you know, it's easy to think that we'll get some relief during the winter when the rains arrive. And certainly, in terms of burning fires, we will. But there's also a lot of concern about whether we'll experience this flash flooding or debris flows in places that have been affected by the fires already.

Another thing that I don't think is talked about as much is the mental-health aspect of living with wildfire. You know, many of the people who lost their homes during the Camp Fire, a few years ago, that destroyed the town of Paradise, in the Sierras in California, were ordered to evacuate during one of the wildfires that's burning right now. And that trauma of wondering, "Am I going to lose my home again?" you know, "how many more times can I do this?" it really does wear on people, understandably. So I think that, as we start to really internalize what it means to live with climate change and to live with these threats year after year, people will need help coping with that just so that they can stay sane and functional despite all the risks that they're facing.

And then, finally, one thing I'd mentioned is that, you know, we have, right now in Oregon, roughly 500,000 people are under evacuation orders in the state. And so, that's 500,000 people that are trying to find safer shelter in the midst of a pandemic. So, we've heard stories of people, rather than going into a shelter that they feel is too crowded, just sleeping in their cars. You know, people who are questioning whether they should go and stay with an elderly relative who lives in a safer area and isn't being threatened by wildfires because they don't want to expose them to any COVID-19 risks. So, you know, these kind of intersecting disasters play out in so many ways for everyone who's affected by these fires.

Colleen: What are some of the short-term and long-term solutions?

Kristy: In the short term, there are going to be many decisions that homeowners and communities face as they look to rebuild from this year's wildfires. Many communities in California have adopted standards for the vegetation that you can have around your house and how much of a buffer you have around your house so that, if a wildfire does strike and all the vegetation around your house, it won't necessarily threaten the structure itself.

We also may need to be taking a hard look at where we are living. We've seen a major influx of people into areas that we call the wildland-urban interface. So, these are these beautiful communities that you find in the west where you've got houses developed right up against beautiful forests. And those zones are, unfortunately, the most risky when it comes to wildfires.

In the long term, we need to be thinking about policies that really limit our greenhouse-gas emissions. So, as our emissions of CO2 and other heat-trapping gases build up in the atmosphere, the consequences for wildfires will get worse and worse. So, if this is truly a problem that we want to tackle in the long term, we need to be looking at reducing our emissions as quickly and as deeply as possible.

It's also true that our forest-management practices have for decades contributed to increased wildfire risk. So, for decades, there were policies of complete fire suppression in the west. And that allowed the undergrowth in forests to build up. And so, we're now really primed to experience these big fires because there hasn't been the natural periodic burning of that sort of...that vegetation that's closer to the ground. So we do need to be thinking about policies like controlled burns that will help to heal and rejuvenate our forests and make them less prone to the really big wildfires.

Colleen: Can you talk a little bit about the public-safety power shutdowns?

Kristy: Sure. So, many people may be surprised to learn that the vast majority of wildfires in California are caused by people. This year is somewhat unusual that we have so many fires that were sparked by lightning. Typically, we see a lot of fires sparked by electric lines, as well as by sparks from a car. And I'm sure many people have heard that a couple of the fires this year were sparked by gender-reveal parties that had, you know, firecrackers that went awry. So the public-safety power shutdowns that have been implemented across California, both last year and this year, are attempts by our utilities to reduce the risk of electrical lines sparking a fire. And they are instituted when conditions are particularly conducive to fire.

Forests sequester a huge amount of carbon from the atmosphere. If you think about it, a 200-year-old tree has been pulling carbon out of the atmosphere for 200 years, which is pretty incredible. And the same is true for the soils that those trees are growing in, they also retain a lot of carbon from the atmosphere. When we burn those trees, and sometimes the soil underneath them gets burned too, we release all that carbon back to the atmosphere.

If you can stretch your mind back to January for a minute, which feels like a million years ago, Australia was experiencing its own horrific extensive wildfires. Since then, researchers have estimated that the fires released over 800 million tons of carbon dioxide into the atmosphere. Which far exceeds the country's emissions from fossil-fuel use in an average year. So we do need our forests to be healthy. Part of a healthy forest is some degree of fire. But we want to maintain and maximize the amount of carbon that our forests can store. Because, as we saw with those Australian wildfires, so much of it can get released back into the atmosphere and just contribute to further global warming.

Colleen: Kristie, thanks so much for taking the time to talk to me about the wildfires. I'm sorry we're always talking about very heavy topics.

Kristy: You know, I think climate change is something that's on everyone's minds out here. And it's hard to always come onto your show and feel like I'm talking about depressing topics. But I also think that, for many people, the gravity of climate change feels very far away. And for many of us, here in California, it's incredibly immediate. So I appreciate the opportunity to talk about it to people who may not be experiencing it so viscerally right now.

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