Stuff You Should KnowWildfires consume an annual average of 5 million acres in the US. But what causes wildfires? How do they become so powerful? More importantly, how do we fight them? Join Josh and Chuck as they take you to the frontlines of the fight against wildfires.
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Good morning everyone. It's July eleven. What No, it's modern times, but this dates back to July eleven, and it is my select pick of the week. How Wildfires Work. This one's important. That's why I picked this one. Everybody. Wildfires are still happening all over the place every year. It seems like they're getting worse and worse because they are. So this is a good podcast to educate yourself on wildfires and how to prevent them, how to fight them, and how they get started in the first place. So enjoy How Wildfires Work. Right now, welcome to Stuff you Should Know from House Stuff Works dot com. Hey, and welcome to the podcast. I'm Josh Clark. There's Charles W. Chuck Bryant right over there, and this is stuff you should not That was my shatner. I told you I worked with him think on a podcast. Right, he was puffy and stuffed in a suit. He's nice though, Right, he was super nice. And heck, I uh, every time I'm wearing wear a suit, I'm puffy and stuffed in a suit. So I'm poured into my suits, poured in liquid. That's great. So, and that's absolutely not true. By the way, Chuck yes, Um, I have a couple of stories for you. I have a specific story for you. But you have this too, right, did I give you this? Yes? Okay? So um in uh two thousand two, Right, there is a guy who worked for the Bureau of Indian Affairs and he was a firefighter for them. Right. He went onto the Arizona Apache Reservation and he started a wildfire intentionally. Okay, So he's an arsonist. Yes, he's not an arsonist for fun or because he's crazy? Um? Or what was it? Uh? He was curious, highly curious. Remember that was a trade, that was trade curiosity setting fires. Um. He wanted work, all right. Leonard Greg Leonard Greg was his name. Um. He uh set this fire and unbeknownst to him, at the same time you do. There's a woman, um, who had run out of gas not too far away, right, um, And she saw that there was a news helicopter covering the fire that Leonard Greg had just said. She didn't know about either, but she didn't feel like walking, or she felt like she couldn't walk, so she set a fire to try to get the attention of the news helicopter so that it would come rescue her. So she didn't have to walk to go get gas. That's pretty amazingly awful. So, um, I guess her last name was chet is Key. Because the Rodeo Fire, which is what they all, the fire that Leonard Gregg's started, collided with the Cherisky fire, and um, it was a conflagration. Ultimately four hundred and sixties seven thousand acres burned, including four and it was the largest fire in Arizona's history. And this is two thousand two. So Greg, I don't know what happened to the woman, but Greg was found guilty of arson since the ten years in order to pay twenty eight million dollars, which as an occasional firefighter for the Bureau of Indian Affairs, I would imagine he didn't have. Yeah, when that never happens. You always see that, like their awards so and so this, and they just don't pay. It's just like a symbolic award. I guess right, you'll know you'll never make more than fifty of your wages again kind of thing. Yeah, But what's crazy is not just that this lady set this fire because she wanted to get the attention of a news copter, or that this guy set a fire because of a desire to get work to put the fire out. Yeah, but because they're not the only people who have done stupid stuff like this. They follow in a long, grand tradition of people who have set wildfires for all sorts of different reasons, and a lot of them to get work. Yeah, you have a list here. And of course we're not we're going to praise the firefighters, not like we're saying a lot of these firefighters starting fires. But it does happen more than you would think. I imagine we'll probably throw some more out later on. But first, chuckers, right, let's get to wildfires, how they work, what affects them. The fire triangle. Yeah, we should probably start with the fire triangle because it relates to not just forest fires or wildfires, but all fires. All fire Josh requires three things. Um fuel obviously to burn air to get oxygen to the fire, so you know that we all knows. We all know that makes the fire burn hot and bigger. And then the heat source to bring the fuel to the ignition temperature to begin with. And they call that the fire triangle and the goal of a wild firefighter, and I guess probably more so a wild firefighter is to remove one of those three components from the scene, and that will give them a better chance of extinguishing the fire. Yeah, if you can bring the temperature down, or starve the fire of oxygen something, or get rid of the fuel. Yeah, all three of those things have to exist. And the reason why, Like, if you look at wood as a fuel would as it pertains to fire is just a um solid store of hydrocarbons that are released when the wood is heated to the flash point, to the flash point um, and those hydrocarbons at the flash point bind with oxygen in the air and it combusts thanks to the spark thanks to the heat. Yeah, and the flash point. Everything has a flashpoint. Apparently everything will burst into flames at some point. Like Ferret Hype four fifty one is supposed to be the flash point of books. Yes, right, yes, which is very cool. Title woods flash point is um five hundred and seventy seventy two degrees fahrenheit three hundred if you're into celsius, if you're into that kind of thing, and uh, that's when would will burst into flames. Yes. Um, I've got a couple of just quick stats here about five million acres of woodland burn every year in the United States, and I got a different set that it was one point two million. But then I looked I saw that that sat Yeah, I looked at the past decade five point nine million, five point to nine point three, nine point eight, eight point six eight four or seven three and seven, So that's about five. So I trust that one. And that is dude. In two thousand nine, I'm sorry, let's go to two thousand and six, there were ninety six thousand three five fires wildfires in the US. It's a lot of wildfires, isn't that crazy? And what's crazy is that four So those are started by human activity? Yeah, a little more than four fasts And that's nuts. Like, I mean, there's a whole thing called lightning season, right that when combined with this, um, this type of weather called fire weather, which is very very dry, maybe drought like conditions UM during warm summer months when it's very hot out um. And all it takes is like apparently like a train wheel causing a spark off of off of the rail into some tinder and then bayam, you've got a wildfire. UM. But even all those uh, don't account for more than a fifth of wildfires. The rest are like people throwing cigarettes out or looking for work is firefighters, or not putting out their fire when they're camping. Yes, that's a big one to um. I have another couple of stats from FEMA. There are total there are a hundred and seventies six thousand intentionally set outdoor fires every year in the United States. And the lot of those I think, uh, they're prescribed burns, right. No, no, no, that that's like people acts of arson. Yeah, but it's uh, only you know a certain amount of those are wild I think sixty three are outdoor fires vegetation fires. So the others are like trash fires, rubbish fires. Yeah, exactly, all of them make smoky the bear weep. Yeah. True. So, um, there's fire weather, there's lightning season four fifths, so fires are started by humans more than four fifths, he said. We know about the fire triangle, right, so once combustion is started from whatever the sources, there's a lot of factors. Well, no, not necessarily. There's three large factors that combine too. I guess give us an idea of what's going to happen with this forest fire? Right now? Are these are these fuel characteristics are like how facet will spread. No, it's fuel, weather, and topography. Those are the big three. And then each of those kind of has a few subcategories. But the but fuel, the amount, in the type of fuel, the the type of weather that that's going on, like is it fire weather is it not? And in topography the lay of the land, like if it's a lake, that's not good topography for a forest fire. And I'm going to use forest fire and wildfire interchangeably. I didn't see anything that said that they're not one and the same. Well they are today at least forest fire just kind of rolls off the tongue a little more for me. Yeah, my thick tongue. Law said wildfire, And I keep saying wild flower to Jerry, is it wildflower or wide fire? Ye? Wide fire? I wanna go forest fire could be a wide fire, that's true. Huh uh. So fuel uh you need a fuel obviously to get the wildfire burning. In what they call the they call it a fuel load is the amount and it's a measured amount of fuel available per unit area and it's usually tons per acre. So they there they can actually they're good enough to guestimate that you like the biomass of like all this dry grass. Yeah, like they know, like, man, this is gonna be a bad one because we've got to you know, I don't have any numbers, but whatever fuel load in this area of the Colorado National Forest. And what's interesting is is, um, you would think that the fuel load if if you do it in weight, because it's tons per acre, right, that depending on the type of fuel, like if it's grass, if it's lighter, that it's going to burn more quickly because it has less of water. Yeah, right, true, because that's a characteristic of the type of fuel, is how how much moisture it has in it. Yeah. And the density like twigs obviously will burn faster for two reasons. One is because there's it's not as densely packed, because which will give it more oxygen. Yeah, there's less surface area. Yeah. And the second is it's smaller and it dries out more quickly. Yeah, it's not like drying a tree or a log. It's got to take a long time to dry out, right. And then the same goes for density with like say tots of pine straw, right if it's very densely packed. Um, it's going to retain moisture in the middle, which makes it harder to burn. Anytime you've ever set pine straw on fire, you know, k it smokes a lot if you'd throw a big mess on your fire, right, But if it's kind of spread out, it's uh, it drives more easily and it lets more oxygen in between it, which is another need for fuel. Yeah, and a small fuel material they call flashy fuels. And they were like four fingered rings, right, and on a chemical level, they it varies on how long it takes these things to ignite as well, beyond the fact that it's just like more dense or bigger or more spread out. Right, Like when I go camping, I will dry out camp firewood beside the fire and you can hear it, says, you can see it. You can see the moisture sizzling from the log and then you just inch it closer and it'll just boom flash point. That's how it happens. Yeah. Oh another thing, josh um. As the fire pushes forward, it's what it's gonna be doing because there's so much heat associated with it and smoke, it's gonna dry out the stuff the fuel in front of it. So by the time it gets there potentially, I mean, that's why wildfire happens. By the time it gets there, it's already dry and ripe for the picking. Yeah, and it's just gonna keep burning and keep burning. There's nothing to stop it basically, that's right. It feeds itself. Um, something else that feeds it. So that was fuel, right. Yeah. The second category or of factor that really determines how wildfire is going to go is um weather. Yeah, big time. And you know when you think of weather, you think, I will you know, rain, snow, If it's raining, then of course the wildfire is going to go out. They point that out in here too. But yeah, I thought, yeah, okay, I thought, um Kevin went to a great Yeah, he definitely. He dotted his eye on that one, he did, because yes, obviously, if it's pouring down rain, it's going to keep everything moist. Or if it's been raining for a while, humidity helps, yeah big time. But the aspect of weather, um that probably has more of an effect than any is wind at ye. So you've got wind outside of the fire, which is going to push it along, push it in one direction or another. Well, it's very unpredictable. That's one of the things. The winds, especially the dry Santa Ana's in California. It's already hot and dry wind, so it might as well be fuel, right, Well, I guess it's sort of his fuel well traditionally, but it doesn't necessary it's not necessarily fuel, but it brings more oxygen to the fuel too. Yeah, exactly right. Um, so it pushes fire along. It's an oxygen delivery system. Wind is um and it doesn't. There's a guy who's interviewed in this article. His names Dr Terry Clark at the National Center for Atmospheric Research, and he's created this model called coupled Fire Atmospheric Dynamics. Pretty cool, and basically what he's doing is figuring out how fire interacts with the surrounding atmosphere and vice versa, because apparently they feed off of each other. Yeah, fire can create its own weather system and weather pattern. Yes, you've seen it before, Like in a really hot fire, these little tornadoes come up. It's a firewhirl right. Um, those can be enormous. It's basically like the heat from the fire creates a vortex, and the vortex is customarily horizontal, but if something gets under it, it can stand upright and it becomes a fire tornado that can throw the whole logs. I can throw a burning tree like a mile. It's a it's a it's a monster, and it can throw it a mile into where there previously was no fire. And that's why file uh forest fires are so hard to fight. One reason why they are because all of a sudden, you're fighting in on one front and you've seen them to leap from the tree tops, and all of a sudden, dude, it's on this side of the mountain now right. It's scary stuff and treetops specifically, by the way, that's a that's a type of fire onto itself. It's that's that's a crown fire, is what it's called. That's right. Um, there's a these uh fire whirls right, the fire tornadoes they don't necessarily have to follow that. That um, that process of starting out horizontally and standing up and then moving like a tornado. There's another thing called a hairpin fireworld. Is this the forward burst? Yeah? This is amazing. Basically it's like the fire develops so much I guess heat, it's vortexas do It's vortices do that it shoots forward like a flamethrower. And apparently these things are they get up to like sixties six feet wide, right yeah, Um, just they can shoot three hundred plus feet at a hundred miles an hour, just all of a sudden, like the fire just shot a hundred feet forward at a hundred miles an hour, and then in an instant, all of a sudden, your fire is going in a if not a different direction and additional direction. Right because tracking these things, predicting these things, it's we've figured out or Dr Terry Clark has figured out, um that it's not just the atmospheric conditions, it's the fire creating its own stuff, its own wind, yeah, and just moving from both of these living thing yea. And they call that spotting if if they if it tosses embers to another spot, they call that spotting. And if it if it starts a fire obviously right um. And then temperature also is another factor. If it's warm out hot, um, you know, obviously that's an extra sixty hundred degrees that the temper that the sun doesn't have to heat something up to. Yeah you know, yeah, you never that's why they burned mostly or most hot and wild during the day during the afternoon, um, California. Like, I had to get used to camping in California because in Georgia, George is like a rainforest man. It's like there's never any fire threat. No. Plus it's so muggy. Yeah, it is so muggy all the time. There's no way you couldn't start a fire if you want to. You can't even strike a match outside right now. But uh, well, I'm just used to camping with a great, big, awesome camp fire. But once I headed west into like Colorado and New Mexico and California, they have you know, every state park in national park you go to a national forest says have signs that say you know, fire risk um high, no fires at all, or you have to apply for a fire permit with the the camp camp rangers camp rangers forest rangers. And uh I had to get used to either sneaking my fire, which is not right in risking fine, or not having one at all, which thinks, why don't you just go apply for a permit? Well, sometimes it was the fire risk was so high you're not to have one at all, And I would still have one, and I probably shouldn't be saying that, but I'm super super careful. I didn't when I when I was living in the van for a little while. Um, I camped on the northern rim of the Grand Canyon and I started a fire, but I don't I didn't see any signs that said no fire or anything, but I wasn't. I could have totally missed it. Probably no one said anything, though. Yeah, and you know what, I was completely irresponsible for doing that. Just let me go on record and say that it was not the right thing to do, even though I was super careful, because accidents happened, and I could have easily been that jerk that like didn't see the ember get away that started a forest fire. So I want to say, I mean, if you spark from a train's wheel can start a forest fire, then yes, very easily a fire that you started start a forest fire. That was very good, Chuck, way to see o A. Well. I didn't want to sound like I was bragging about it, like, oh, I was super careful, so it was cool. This is it was not cool. There's this guy on Um, yeah, I didn't take care of breaking Okay, did you ever watch Malcolm in the middle. Oh yeah, um, there was this one. There was this one scene, um where the mom was telling the dad he was he was saying that she was giving him grief about the stories that he was telling his kids, and he's like their cautionary tales, and she goes cautionary tales doing him with It was so cool. I enjoyed that show for a long time. But like all shows when it's about kids, when they got a little too old, you know, all of a sudden, his voice is down. Well no, he he cashed out, like right about that time. He was like I'm out. Malcolm himself. He was like, I've I've got fifteen Porsches and I'm very happy. I'm done. Well, yeah, he went on to his big movie career. Yeah, that's right. Sorry Cranston. Though he's uh have a scene breaking bad. But it's supposed to be amazing, all right. The last thing, Josh is topography. That's what we talked about. A steep slope, it's gonna spread faster, usually spreads uphill. Even though leave it to Australia to do something weird. Dr Terry Clark says he as a case study in Australia, where the fire actually burned down a sloped mountain, which is pretty unusual. Yes, normally it burns up for a couple of reasons. The ambient wind um usually blows uphill. Um. The steeper the slope the better because the fire, the smoke and the heat. Well, for the fires concerned, it's like, give me a steep mountain because the fire would be standing almost upright then, and the smoke and the heat coming off the fire is um really drying out the fuel load ahead. So most of the time they burned upward up the mountain, and then they reach the crest and they're like, I should have thought this through because now I have to go down and I can't ye, which is good for fighting the fire, not good for the fire um they can besides burning all the vegetation, which is can be really bad. Uh. It can lead to things like erosion and mud slides later on because you mess with the with the ground like that and it's not stable like it once was. Yeah, I mean, like the one of the roles that roots a root system plays is holding the ground in place. And if you burn the tree and the roots system out, it's just soil and the nice heavy rain comes then and that very thing happened Josh and storm King Mountain near Glenwood Springs, Colorado, two thousand acre forest burned and the underbrush burned on the steep slopes. And two months later they got a lot of heavy rain and it literally poured tons of mud and rock onto a stretch of Interstate seventy like engulfing cars, sweeping them into the Colorado River, all because of the fire months months ago. And we've seen one sides before. Remember Guatemala. Oh yeah, remember like down the mountain there was still that path. You could see the where the path came tree standing on this village where they'd never unearthed the people and it was like people's kids were running around. Yeah, it was so sad. Where we were standing was like six ft higher than it once was, right, yeah, alright, six at least. I would say that's awful. So, Chuck, if you want to put out a fire, well, first of all, they're beneficial, though we should say that at times burning the underbrush of a forest can prevent a larger fire later on, So they do have like prescribed burns like you were talking about, Chuck, I inadvertently started a book club by mentioning again recently, have you noticed a lot of people have been writing and saying like, thanks man, I'm starting yea, and they're like, what about Yes, it's another book that's a fake book though, Oh is it? It's yeah, that's the one where the guys like the Chinese made it to South America. Mexico wrote article about it, and I pilloried the guy. Okay, yeah, it's very he has very shaky, shaky evidence. That's fascinating stuff. But well have we not podcasted on that. Let's do it all right? I read that today and I was like, why haven't we done this yet? Oh, we can totally do it. Okay. I think it took a little while from me for the bitterness to like my mouth like after I wrote that one, because the guy was getting tons of pressed at the time. But anyway, anyway, anyone who's read knows that North America it was basically a managed forest, and one of the ways that it was managed prior to Columbus was through prescribed burns. Like it there. It is very beneficial. It burns away the underbrush so you have less potential for accidental fires. Right, Remember we talked about recessions are kind of like that um and the it gets rid of disease, provides nutrients in the soil um awesome show. After you'd like, you know, hit the peace pipe, just kick back and watch a forest fire go. So let's talk about putting these things out. Josher's. Uh. They have a couple of categories of the these elite firefighters. They're called hot shots and smoke jumpers. The hot shots. What's so funny, that's the names they give them. Yeah, that's pretty let's say that's pretty bad. Are alright? Hot shots They work in twenty person teams and they are trained there on the ground and they were trained to build mainly to build fire breaks. And that is when they strip the land of fuel ahead of the fire, or they will burn it ahead of the fire. Yeah, to stop it. There have you ever seen that? God's must be crazy too. No. The dude, the main dude, I can't remember his name. He um. There there's a brush fire coming like a prairie fire, savannah fire coming at the main characters, and they're about to be engulfed in it. And the main bushman runs and grabs like a piece of grass or whatever and sets fire to the grass behind them that they are running into and burns it and then basically creates a circle. It's a backfire firebreak, and they're all standing in the circle where there's no more fuel any longer. It's completely and utterly genius. Well it is. And it's also you have to be you have to really know what you're doing. You know, you have to put it in the exact right spot. I know that sometimes they'll do the firebreak and the fire will leap over that, and then that's kind of make you feel like, yeah, there's nothing we can do well in a lot of cases. I mean, it's like I remember, was it two years ago, was or maybe it was three years ago when they had all those wildfires, and uh, I remember thinking like what we can do medically, and like, we can, you know, put a man on the moon, but we can't stop a fire. And it's that out of control because it's so huge and overwhelming, very deep, thank you, not deep at all. Actually. And there's there's smoke jumpers, which are hotshots that jump out of airplanes, right yeah, and there's only a couple of hundred of them in the US, which I can imagine that's a really specialized job, and you have to be a tough mug to do that. That would be Hawing Long. He did in in Firestorm, I think he was. I didn't see it. Not many people saw it, actually, but I did copy the the description from IMDb. I thought it was just about like a firefighter and like forest fires, but of course, because it's Hollywood, they added some plot to it. Firefighter Jesse Graves has to save ornithologist Jennifer and other people in a forest fire. Like I thought that was it, but no, it was set up by the lawyer of a convicted killer, Earl Shay, who escaped from prison with several of his inmates, posing his firefighters to recover thirty seven million and stashed loot. So they were acting. They started the fire and purpose it was sort of like the guys who posed as UH ambulance drivers to get the dude out of prison. That sounds awesome, actually, I mean the plot description sounds pretty awesome. You can tell you hear like Howie Long, it's going to be awful, But like I'm sure the writer of that was like, okay, yeah, and then he hears it's gonna be Firestorm starring how he long, and he's like, I'm sure that the writer Alan Smithy was pretty psyched that that is project for a little while. So chuck, oh uh, you can fight a fire using an air corps, right, Oh yeah, that dropped fire retardant on the fire. You've seen the news footage the red stuff. Yes, Or they can drop tons of water and have you ever heard that urban legend? M oh yeah, but what is it? So there there is a forest fire somewhere we'll say California, and they put it out, and like six months later or whatever, some hikers walking through this area and looks up and notices that there's a scuba diver stuck in a tree, right, but the rebreather on and the the mask on and the flippers and everything, and um, he's dead. And the hiker can't figure out what's going on, and you know, leaves the forest and tell somebody about it, and they start doing some research and they figure out that he was scooped up by one of these planes that goes out to the ocean and like steps up a bunch of water and comes and dumps it on the totally not true, right wildfire. Now, the fire, that's a good one. Yeah, it is a good one. I hate it when you burst Urban Legends though, because it bursts so many bubbles right now, so it's so beneficial. Like, yes, I know it's stings right now, but in about forty five seconds, you're going to feel like a smarter person, right, that's true. We mentioned the fire retardant that is not just red stuff. It is um a chemical retardant containing phosphate fertilizer, and it cools down the fire slows it down. It's like, uh, it's main ingredient is water though, so it's like puper superwater as far as you know. I was thinking about when when I was reading about smoke jumpers. Um, the the human cannonball thing that DARPA came up with would be perfect for that. You could just be like to shoot a bunch of smoke jumpers into the like over the fire into where you want them. You don't need the parachutes or something. Yeah, I can't imagine a smoke jumper's job like landing in the middle of that stuff. Yeah, that's crazy stuff, amazing and um. We also want to give a shout out to always Great Movies starring Richard Dreyfuss. It was no always Oh, I thought you said, we always want to give a shout always remember. Yeah, that was a good movie. John Goodman, Holly Hunter, Richard dreyfuss Um, and that handsome dude who I don't know. Yeah, that's right, the guy that played the handsome guy. And it was a remake of I think a guy named Joe or something is h And I also I believe Audrey Hepburn's final film was it because she was darling in it? She was, she was pretty till the very end. Is that it? That is it? Okay? If you want to know more about forest fires, you should go into the beloved venerable website that we work for, how stuff works dot com and type in wildfires and we have it as one word, right yes uh. And if you type an ends, canna bring up a very cool article with some really great photography to um. I think the page one or page zero pick is just awesome looking. Um. And since I said handy search far, that means it's time for a listener mail. It's not. Oh yeah, that's right. I don't have a listener mail for this one. Josh, and I was trying to think of what we could do instead. Would you come up with. Well, I thought about a call to action saying that you know, that would be great if you could go to iTunes and leave us a rating and a review, because are bad. Some people hate it when we do that, you know, like we're just begging for it or whatever. It's beats a pledge drive. Yes, it does, Chuck. Do we ask that much from you guys? Really? No? So so so. Actually we finally worked that out. Call to action or how about some love for Jerry via email too to be great? Oh that's nice. Some Jerry questions or both. We'll tell you all about Jerry. Yeah, ask us really personal questions about our life answer and totally we've just been waiting for everyone to ask Yeah. Um, you can ask those questions all sorts of ways. Um. First, if you want to go give us a rating a review on iTunes, that's very nice, if you thank you. Um. But if you want to ask us a question about Jerry, you can tweet to us. We have our own Twitter feed up to fifteen thousand followers. Did you know that? Yes, s y s K podcast one word um. And then of course we have our great Facebook page. Um, that's Facebook dot com slash stuff you should know, And you can send us a regular old email and you can listen to us on WFMU if you're in New York or New Jersey. Uh ninety one point one Friday's between seven and eight pm. The Stuff you Should Know Radio Public Radio version or ninety point one in the Hudson Valie Hudson Valley. Um and and is that not New York, New York's down the Hudson Valley. Where's the Hudson New York State? So that's up stick? Is that where Albany is to keep hearing like everybody in law in order to talk about when they mentioned the governor huh um or you can send us a regular world email to stuff podcast at how stuff works dot com for more on this and thousands of other topics. Is it how stuff works dot com
