Once and for all — trees do not explode

I asked a fire scientist

Elkhorn Fire
Elkhorn Fire. Shasta-Trinity National Forest in northern California. September 3, 2020. Photo by Mike McMillan.

September 15, 2020  |  7:45 a.m. PDT

Yesterday President Trump flew in to Sacramento McClellan Airport to receive a briefing on the wildfires ravaging the state. Before he met with the Governor and fire officials he stepped before microphones and provided his opinion about what led to the numerous fires in Oregon and California.

“There has to be good, strong, forest management,” he said, “which I’ve been talking about for three years with the state so hopefully they’ll start doing that.”

(The federal government owns nearly 58 percent of California’s 33 million acres of forestlands, while the state owns 3 percent.)

Then the President talked about exploding trees:

“But with regard to the forest, when trees fall down after a short period of time, about 18 months, they become very dry, they become really like a match stick and they get up you know there’s no more water pouring through and they become very, very they just explode. They can explode.”

The myth of exploding trees may have originated with a classic film about wildfires, “Red Skies of Montana” which showed firefighters being harassed by exploding trees, thanks to movie magic. Then the book “Young Men and Fire” mentioned “the occasional explosion of a dead tree”.

In my 33 years of fighting wildland fires I never saw or heard a tree explode, and I don’t know a reputable firefighter that has.

In 2016 after the late Senator John McCain talked about the Chedeski and Wallow fires in Arizona and “trees literally exploding as the fuels that have accumulated around the bases of the trees burns up,” I reached out to the firefighter community asking if anyone had ever seen a tree explode. No one said they had.

When lightning strikes a tree it can explode when the moisture inside is converted to steam in a millisecond. And maple trees can explode in below freezing temperatures when the sap freezes. There are unconfirmed reports that eucalyptus trees in Australia can explode in a fire but I’m not convinced this is true. I understand that heated gasses or sap can shoot out of a crack in a eucalyptus tree and can be ignited during a fire.

Frank Carroll, in a comment on yesterday’s article about the President’s remarks, said he possessed a video shot with a wildlife camera of a tree exploding in a fire. He also said, “Rothermel theorized that the moisture in the tree is superheated and caused the rapid expansion of gasses that go boom.”

(UPDATE: Mr. Carroll sent me the video, with permission to post it on YouTube. You can judge for yourself if it shows an explosion.)

Dick Rothermel fire research Ember Award
Dick Rothermel was given the Ember Award for his wildland fire research, at a conference in Missoula in 2014. Photo by Bill Gabbert.

Since his name had been invoked, I reached out to Richard Rothermel, who is a retired fire scientist. In 1972 he and others developed the Forest Service’s first quantitative, systematic tool for predicting the spread and intensity of forest fires, which introduced a new era in fire management. And surprisingly, it is still the main tool being used today. Many researchers have produced alternative models, but none have made it into the hands of firefighters on a widespread basis.

When Mr. Rothermel began researching the behavior of wildland fires, he had just been downsized from a shuttered Department of Defense program that had been working to develop a nuclear-powered airplane.

I told Mr. Rothermel what was said about him, and asked for his response. He replied within a few hours:

“I have been out of the fire business for a long time and I don’t recall discussing exploding trees. Thats not to say I didn’t, but theorizing the problem now, here is what I think. There may be different concepts of what it means for a tree to explode. One could be that the foliage suddenly bursts into flames due to a massive amount of heat engulfing the tree. That I believe could happen.

“The other which your question prompts me to believe is what is meant by an exploding tree is for the trunk to become super heated sufficiently to cause the moisture in the tree to suddenly become steam with resulting expansion which would shatter the tree. In my years at the fire laboratory I never heard anyone report seeing this or finding evidence of it.

“The problem is the timing, a tree at the fire front could be engulfed in both convective and radiant heat which would transfer heat to the tree’s surface very fast, but the heat would then have to be transported by conduction to the moisture in the cambium layer. Conduction is a very slow method of heat transfer in woody material. In the situation under discussion the fire would be spreading extremely fast and the fire front would have moved on before the heat could have time to boil the water in the cambium layer and cause a steam explosion at the fire front. What could happen after the front has passed and the fire continues to burn if fuels are available is anybody guess.”


UPDATE, September 18, 2020  |  1:32 p.m. PDT:

I first wrote about the myth of trees exploding in 2016 when a senator talked about “trees literally exploding”. I noted then that at least one book and a movie also propagated the myth, and I wanted to dispel it.

When Mr. Trump said trees can explode, I decided to write a followup to the 2016 article, hoping to clear up any confusion, since trees do not explode.

Some of the readers of Wildfire Today were offended by what they saw as criticism, and bent over backwards to make what he said seem reasonable. A person might wonder if they would have put up as strong a defense if the same words had been spoken by a different President.

Bill Gabbert
Wildfire Today
Wildfire News & Opinion, since 2008

Typos, let us know HERE. And, please keep in mind our commenting ground rules before you post a comment.

Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire. Google+

77 thoughts on “Once and for all — trees do not explode”

  1. 6 seconds)
    Search Results
    Featured snippet from the web
    Image result for can eucalyptus trees explode in a fire
    Exploding trees also occur during forest fires and are a risk to smokejumpers. In Australia, the native eucalyptus trees are also known to explode during bush fires due to the high flammability of vaporised eucalyptus oil produced by the tree naturally.

    Exploding tree – Wikipediaen.wikipedia.org › w

      1. He is probably referring to crowning out. It is a terrifying series of explosions when the heat drives the fuel out of the crowns of the trees surrounding the fire and when the oxygen level is combustible it explodes and repeats over and over.

      2. Years ago, I was traveling through eastern Washington and got caught up in a big traffic stall in the middle of an aggressive wildfire. I saw and heard what I have described ever since as “trees exploding “. When they “exploded”, they also “screamed “. I realize now that what I saw and heard has a scientific explanation and wasn’t technically an explosion or a scream, but that is how I have described that experience for the past 30 years. It was a powerful moment in my life. Made a BIG impression!

        1. If I live tree falls could it not spontaneously combust after a while I’m extreme heat? I have no frame of reference but I have seen hay barns catch fire many times. I’m told it’s when the hay gets put up to green. As a structure FF I know how common it is for mulch to smolder. If the mulch was in a forest of kindling I could imagine describing the tree as “exploding”. Obviously meaning just combusting rather quickly.

    1. You’re absolutely right, and california has 40,000 of these eucalyptus trees! In Black Friday, one of Australia’s deadly bush fire, the heat generated by exploding trees equals to 1500 nuclear bombs dropped in Japan.

      1. Having worked with the researchers who studied the 2009 Black Saturday fires, I can say with confidence that weeks of exceptional heat that peaked above 50C, followed by a dry cold front passage which created sustained winds exceeding 100 kilometers per hour, were the conditions that caused the explosive fire growth. Exploding trees or not, it’s dry heat and wind that create catastrophic conditions.

    2. I was a volunteer fire fighter in Orange County, CA. In all the wild land fires I participate in Orange County and LA County, Eucalyptus and California Oak would catch fire at the base at the low hanging branches and cascade upward. When the center leaves caught fire the sound of the leaves burning was almost the same as a rocket engine burning through its fuel for about five minutes. It was spectacular in the day or night. If you’re talking about the rush of flame running up through a tree as an explosion, humm…ok, but the tree didn’t explode. The flame spread was uncontrolled and limited unless it was part of a wind break or flame jumped from tree to tree or radiant heat started fires in adjacent trees.

      1. During extreme wild fires here at home in North Texas, Cedar Trees did explode. You could hear it and see the debris fly through the air.
        Thus creating more fires as the flying embers set off more and more fires.
        When examining the stump, they were shattered and splintered as though they were blown off.

  2. I agree with Dick Rothermel’s explanation.

    We can’t expect the general public (including politicians) to describe a high-intensity fire the way members of wildland fire community can (or should be able to do so). For civilians, the sudden changes in the sight, sound and feel of low- and moderate-intensity surface fires transitioning to crown fires in conifer forests no doubt conveys the feeling of an “explosion”.

    Marty Alexander, Wild Rose Fire Behaviour, Leduc County, Alberta

    1. Marty; I agree with you 100 %. “Trees exploding”,”sounds like a freight train” and “it’s rolling ” are all Wildland fire expressions often used to describe spectacular fire behaviour to other firefighters. These terms should not be taken literally by civilians or for that matter the media as they need to leave the firefighting to the people who actually do it.

  3. Although not a tree, I did witness fire getting into a stand of bamboo during an Rx burn. The individual “chambers” started exploding and popping as the dead fuel around it burned and heated the water inside. I have also seen eucalyptus burn on numerous occasions and have never seen it “explode”, but have seen it “aggressively torch” due to the oils it produces.

  4. Good follow up on your previous post about fantasy of exploding trees on wildfires.
    I never saw that in decades of forest firefighting, no one I know who has ever done the job of fire fighting has either.
    For,old,firefighters, Rothermel work was,well known.

    It’s true public to this day does not understand forest firefighting.
    We have not,reached enough people nationwide and educated them .
    To most people, structural firefighters are the image of fire.
    They are in cities, rural,areas daily, doing a dedicated job for what they deal,with.
    The voice of Wildland firefighters are not heard enough
    Or forgotten in off season.
    There is a bigger more complex,picture that needs to be part of a very fast education
    In the age of intense dangerous fires on a quicker cycle.

    Keep,up,good,work
    Educate
    Challenge fantasy and cherry picked info with no basis
    Science based information

    Chris Chiverton
    Retired Battalion Chief

  5. Maybe he is referring to Autoignition. At point of tree/vegetation autoignition, it could be characterized as an explosion due to associated rapid expansion/release of gases and drastic increases in temperature. To a person like DT, Explosion sounds more dramatic than Autoignition and more people could relate to it as well. I am sure some are imagining trees physically blowing up into pieces…not sure that is what he is thinking.

  6. Thanks Bill for your relentless commitment to the science and “doing the homework” to separate fact from ungrounded opinion. Mr Trump’s comments in Sacramento are not helpful, let alone inaccurate. I concur with you and a previous commenter that the public has a long way to go regarding fires, forest ecology and the urban-wildland interface.

  7. In my 3 years of wild land fire fighting, approximately 60 years ago, I remember an instance where trees were preheating and would make a kind of whistling noise and become fully engulfed immediately. We referred to it as exploding even though it was not like a bomb. Maybe we are dealing with semantics.

    1. 30 years of firefighting, 9 as a hotshot, the rest on engines and fire management. Have seen extreme fire behavior many times out here in the western states. Never have I seen or heard a tree explode, from near or from far. Have heard various sounds from trees when they burn, but no explosions. When trees fall, they do make crashing sounds. I even had to deploy a shelter once in the 80’s. Not one tree exploded. Also cut a safety zone for the crew on a mountain where various fire fronts hit us. Not one explosion. I also know about time-lag fuels, wind and slope, moisture content, and all the other factors which contribute to fire spread. Check your weather stations, if there is enough years of data, it could tell you what percentile the weather factors were compared to past years. Retired now, Happy Firefighting!

  8. Excellent piece and I think that your usage of the John McCain comments provides some excellent political counterbalance. Good job.

  9. I think we’re groveling around semantics with this “tree explosion” topic.
    In all my years of fire fighting, I never once saw or heard of a “wood scientist” at or near the front of a fire. These aren’t lab exercises when you have a fast moving fire, preheating fuels very long distances ahead of a front (yes, there can be more than one “front” on a fire), so hot and intense that hair curls on the back of your neck as well as your ears, and sometimes (back in the day of aluminum hard hats) you could even smell the paint from your hat. Under those conditions, I have experienced a tree (oak) explode so lou dly that I hit the ground. This is why I say “semantics” above; to some, the tree exploded; to others, the wood didn’t explode, just the leaves and smaller twigs.
    OK, so be it. When you’re running away from such a quick event, it really doesn’t matter. I think we’ve beat this topic to death.

  10. ‘Once and for all’, some trees, like eucalypts, under the right conditions, can definitely ‘explode’. Not like a bomb, but that’s not the only kind of explosion, now, is it.

  11. Bill
    For those of us in the profession, this kind of terminology we all know and use is just lack of knowledge on the part of the public and our electeds who are ultimately getting their sound bite in the media. And yes boomerangs back to us for lack of outreach.
    I for one with well over 30 years of wildland firefighting service have never seen a tree explode.
    And I will also say we are our own worst enemies when it comes to perpetuating this kind of thinking. I cannot count how many times we as an industry have used comments in a 209 like, “explosive fire growth”, “explosive fire activity”, etc. Or worse yet during a press conference or public meeting, again many many times. How can we expect the community to not pick up on and use these terms even if out of context?
    I think to pin this on a politician of one party or another is a bit one sided. Just yesterday Biden was quoted as saying that we can see the fires and smoke from our satellites a million miles in space. Wow that is some kind of satellite when the moon is 238,000 miles from Earth. They inevitably repeat some kernel of a statement they heard at some point.
    Let’s all try to keep our political pants pulled up.
    😉

      1. Thanks Bill

        Please understand I a m not having a go at you, when I say I didnt even know we had satellites orbiting the sun.

        Science, or what mankind does with it for good (or bad) never ceases to amaze me.
        keep up the good work

        from down Under

        Andrew

  12. Trees don’t explode in the way described by the Republican President. However, as a fire fighter I was on a fire in the Shasta Trinity National Forest in which trees did explode. I did not see it, being, thankfully, across the canyon, but I did hear them. Super-heated by flames running (flowing) uphill, the water inside the tree turns to steam, and – pop – toothpicks!

  13. So many people tying themselves in knots trying to validate Mr. Trumps concept of exploding trees. How about instead of projecting all sorts of fire behavior scenarios into the discussion, none of which Mr. Trump would have any, even the most superficial knowledge of, we instead listen to his exact words. It’s crystal clear what the President was talking about… Mr. Trump was specifically referring to a fallen tree. “… when trees fall down after a short period of time, about 18 months, they become very dry, they become really like a match stick and they get up you know there’s no more water pouring through and they become very, very they just explode”.

    “… when trees fall down… about 18 months later…they become very dry…they just explode.”

    He’s not talking about low intensity surface fire, full tilt raging crown fires, lightning strikes, fires transitioning from ground to crown, torching, auto ignition, spontaneous ignition, rapid expansion of gases, oak trees, fire science, eucalyptus trees, area ignition, conflagration or explosive fire growth. Just stop putting words into his mouth or attributing even the smallest amount of expertise to him. He said fallen trees dry out and explode. It’s really quite simple. It’s really quite nonsensical.

  14. Yep, I experience a tree exploding. Hiking into a fire in the Sierras. All at once the tree (red fir) exploded. We were exposed to huge airborne pieces of tree shrapnel, blinded by the “explosion” and could smell something in the air. A second before the explosion my hair on my arms felt real tingly. O you mean in a fire? Nope.

  15. Well, well well! Yeah, opinions are like belly buttons … everybody has one. Most of our “knowledge” is something we heard or read that somebody else, twice removed, no matter how learned or well believed they are, has said. And most of that is tainted with their (our) own private ignorance. We spend a great deal of time and effort discussing, proving, disproving, tormenting both fact and fiction for our egos and entertainment, stuff that doesn’t amount to a rat’s patootie. And none of us is as smart as we’d like to think we are. If all the energy spent disproving everything Trump, Obama, or the Clintons said could be gathered in one place and put to a constructive purpose, we could build a bridge, or at least a very nice chicken house with it. Or a golf course and a hotel, if so inclined.
    Do trees explode? I for one, am fascinated by anything that goes “BOOM!”

  16. Thanks for checking on this, Bill. It’s clear a number of “reputable firefighters” remember trees exploding in their experience. I sent you some video from a trail camera and some photographs of the 1910 Great Fire and the 1992 Central Idaho Fires that show vast destruction that is simply not explained by any one factor like the wind. We have no empirical evidence of what actually happened because, as another comment mentioned, the fire scientists aren’t there in the maelstrom to witness it. Heat and volatiles cause explosive reactions. Maybe it is semantics and we are all talking about similar things. The photo I sent from Grape Creek on the Boise shows a scene reminiscent of the battlefields of World War 1 following an artillery barrage. It’s worth wondering what would cause a similar effect in a firestorm of unimaginable heat and intensity. The controversy here is with those of us trying to give the President a little slack in his vast ignorance of our work, versus those who just want to keep trashing to poor guy for his clumsy approach to things he knows little about. To his credit, he is not pushing spotted owl habitat as Clinton did, or more wilderness we can lose to even bigger fires. So, there is that….Maybe he’s teachable. We shall see.

    1. Frank, while you undoubtedly have good intentions in sharing with Bill what you consider evidence of proof that trees explode, please recognize that interpretation of evidence isn’t proof. I wouldn’t be surprised if you know many people who agree that the video and photos you mention prove that trees explode, but that’s not how science works. If an alternative explanation cannot be disproven, then the proposed explanation remains theory.

      I’m not arguing whether trees do or don’t explode. I would just like to inject a bit of the scientific method into the discussion. The fact is that the scientific method works – Newton’s and Einstein’s theories of matter, energy and gravity seemed unassailable for years, but the discovery of quantum mechanics revealed failures in those theories and made the invention of countless staples of modern society, such as computers, GPS and LEDS, possible.

  17. Once and for all, eucalyptus trees have always exploded when they catch fire. There are very few eucalyptus in California forests, because they are not indigenous to America. They were imported by the railroads over 100 years ago.

  18. I have been a volunteer firefighter for 22 in the western end of the Oklahoma panhandle and I have many times witnessed trees explode. Pinon pines in the mesa country of NW OK panhandle, NE New Mexico, and SE Colorado do explode in some cases. It occurs in the lower part and roots when conditions are right and the tree is rapidly consumed by fire. Many times I have been hit by pieces of rock or bits of bark when the trees and roots have exploded while doing hand crew work on fires.

  19. Most people confuse rapid burning with exploding. Gasoline doesn’t explode in the engine when the spark plug sparks butttt it burns at a pretty rapid rate. I would bet that most NASCAR and IndyCar mechanics/engineers would say “explodes” in mixed company conversations. The Challenger space shuttle didn’t just “explode” butttt we and the news media say it did.
    JAJAJA

    1. So where is the “division” between explosion and rapid burning – why would you post this
      (Excellent point) without that delineation ?

  20. Alright, I give up. I’ve tried 4 or 5 times to post a fuller version of this but Bill’s comment system just seems to barf when I do so I’ll keep this simple.

    We need big ideas and our current President is incapable of them, especially when it concerns wildland fire. He is tenaciously unwilling to learn about the problem and refutes basic science. It’s not surprising he thinks trees explode when his answer to the problem is to turn the forest into golf courses with clean 50 yard wide strips interspersed througout them. Not that I’ve seen anything truly intelligent or creative on the topic from the other side for that matter either.

    So, I’m proposing a big idea. It might not be entirely but it’s at least something to talk about.

    Let’s establish a National Guard-like structure specifically for wildland fire. Enroll people in the system, give them training and benefits like education grants and access to health care, and require annual training and service outside of call-ups like the NG. Enable legislation similar to what the NG gets to protect them from job loss when they are called up. Establish a national distributed cache of appropriate equipment and PPE to support the call-up crews. Cross train the NG more extensively for air support and logistics. In essence, it would very similar to the National Guard, just without guns. You could even cross-train them for other disaster relief as well. We have 30,000 personnel on the fires. What impact would another 30,000 have if they were trained and equipped?

    I’m not suggesting a whole scale war on fire, just on handling the extreme conditions we find ourselves in at times. In fact a big part of the training of this new group could be WFU or prescribed fires during slower seasons or fuel management work during the off times.

    Let’s at least insist our political leaders come up with something workable even if it isn’t perfect and doesn’t solve anything. As long as it’s something more intelligent than raking the forest and 50-yard wide clearcuts.

      1. Thanks for that, I hadn’t seen that. I figured it could be an entirely original idea but why aren’t we (as a country) talking about some of these bigger ideas? Heck even arguing about it might get us thinking about how to do it and lead to some innovation.

    1. Haha you have never done any prescribed burning I see. A “50 yard clear cut”…..what might that do? These fires w waist high fuel jump 1/2 mile. Prescribed burning in any topography except FLAT, creates its own head wind going up hill……can’t be done. “Raking” the Millions of acres…..I want one of those contracts, can’t be done. Clear cuts and stocked forests burn the same. What would the purpose of the additional trained NG be? City folk

  21. Everything in Red Skies of Montana was true. It had Richard Widmark in it, and he’s an actor. So when Trump says something it’s the truth. He’s a &#%&$5

  22. Really, he doesn’t know what he’s talking about. We may always wonder, like where he got a notion that raking the forest floors would be good forest management.

    Unfortunately those of for us that have been involved in wildland fire science, suppression, and management, this is not a reality tv show, but real life, and a comment response yesterday to scientists about the continued drought and recent 130-degree temperatures in Death Valley, “science doesn’t know” is hard to hear, let alone take.

  23. Do trees EXPLODE? The answer is definitely “yes” but it all depends on the definition of “explode”. “Explode” in everyday colloquial language can be used to describe something that happens very suddenly. I don’t believe anyone would have a problem with this sentence: “An unattended campfire got out of control on a hot, windy day and very quickly exploded into a raging inferno.”

    What a lot of people do not understand about Trump is that he likes to use colorful, exaggerated language to get his point across. I knew what he meant. He did not mean that a tree would explode like an artillery shell. Just that it’d go up in flames so fast that it would appear to just plain “explode”.

    Trouble is, often times Trump gets himself into trouble with his exaggerations. Sometimes his mouth is just plain too big and that might cost him the election – or not. We’ll just have to wait and see.

    Regards,
    Fred M. Cain

  24. I know of two ponderosa pines that exploded as a result of lightning strikes, NOT wildfires. I have photos of one of them that was on the Serentity Trail north of Newcastle, Wyoming last year. My cousins took pictures of another one in the Black Hills this year and posted them on Facebook. In the springtime and early summer the trees become saturated with moisture which expands violently from the heat of the lightning strike.
    Never say never….

  25. To Dave’s comment on trump stating”science doesn’t know”….yes, hard to hear, but even harder to watch. The dismissive and arrogant bravado he projects has gotten really….really old. Makes me want to puke.
    There is a pressing need on multiple fronts for the president to engage with others, including scientists, in a way that creates a sense that we are in this all together and that the solutions, while not easy, will come from a collective effort of hard work and mutual respect….
    To another poster…it’s not just his big mouth….I wish that was true..The reality is he has surrounded himself with syncophants that have no business trying to help lead this country…
    He and his cronies are an impediment and the antithesis to what great leadership looks like.

    Back on track….what hasn’t been discussed is the amount of fine fuels that get built up on the moist years such as 2019….this see saw effect of wet and dry correlates well with a graph Bill published recently.
    Some, not all, of the large fires this year were a result of fine fuel buildup…
    As climate change amplifies these cycles, it will only get tougher and more dangerous as large landscape fuel types are replaced with fire dependent species that depend on and actually help fire.( cheat grass being the classic in much of the west)
    Here in alaska on the kenai, we have a very aggressive native grass that has taken over the beetle killed stands and fire scars to the extent that much of the peninsula looks far different from 40 years ago..
    These large scale changes in the landscape, combined with a warming climate need to be met with the reality that under ripe conditions, firefighting efforts are left largely impotent.
    Fireproofing, equipping and teaching home owners how to protect themselves and their property would be a lot better than recruiting and training national guard..thats something our fearless leader should be talking about.
    I am a big fan of using low volume myster style sprinklers (.2 to .5 gpm) to fireproof the outside of homes and surrounding grounds. Wanted to show our local fire management how they perform and he wasn’t at all interested….
    If fire suppression management think they can just keep doing it the way it has been , then we are in for a long, difficult and mostly unsucessful ride..

    1. What?! You think multiple articles critical of the President is politically motivated/biased? You think intensely analyzing the nitnoid semantics of the word ‘explode’ is boring, serving a political viewpoint rather than the wildfire community?

      Yeah, me too.

  26. If only there were policies to discuss….we could then at least agree or disagree on the substance…
    Instead we are left flailing at one mans lack of desire to offer meaningful, considered content to what is a truly tragic life event for many. Those who have lost everything deserve better…..and that starts at the top. Hint…thats really what this is about…not a certain word that starts with “e”

    If wanting more from your leaders is talking “politics”, then so be it….it’s a discussion that’s sorely needed, and goes to the heart of what forums such as this can offer to those of us who have spent our lives working at..

  27. Just like literally everyone else is doing with every single word spoken by our president, this is just taking one word, pulling it out of context, and getting overly fiddly about the semantics. Even as someone who isn’t his biggest fan by any means, this is getting abundantly silly.

    Also expecting someone with no experience fighting wildfires to know all the bits and pieces about it is equally silly, even if they are the President of the United States. Although to be fair, all of us know if it was anyone else making this mistake, there wouldn’t be anywhere near as big a deal made out of it, and the mistake would be forgiven and treated with comradery instead of thinly-veiled vitriol.

    And for the record, I myself have heard many local firefighters talking about exploding trees in my lifetime, in various fires around the states of Arizona and California. Firefighters, say this. Not media. Were they talking about trees blowing up into bits? Maybe not. I didn’t think to ask them to clarify. But obviously something struck them as being explosive when they witnessed these fires grow into the monsters that they were. Imho, having sat and watched tree after tree “explode” into flames during the Rodeo-Chediski with my own eyes, I don’t think it’s far off the mark to refer to the striking visual of a tree-crowning fire as an explosion.

    Look, I don’t want to be that guy that comes across as attacking you. I very, very deeply appreciate all the information you put out there, and the efforts you go to in order to educate all of us, and I hope you’ll continue to do so. But this nitpicking over every jot and tiddle of this president to be extremely tiring. If he was wrong, used the wrong word, had the wrong impression…honestly, so what? His point throughout all of this was getting support and protection to the crews, and doing what we can to keep more of these horrible fires from happening again. All of which, I think we can agree with.

  28. 1. Trees don’t explode, but they can burn very quickly under some circumstances. But one simple fact may or may not be highly relevant in some contexts.

    2. Slash left in the woods by loggers makes fires worse, and are a great source of airborne firebrands, which generate spot fires and ignite houses. Natural sources include dead branches and forest floor litter. But context is still “everything,” and in addition to the fire triangle, there are other fundamentals like burning sequences to consider. I used to survey trees (late fifties and early sixties) where the North Complex Fire is burning now. There were butt cuts in excess of 13 feet in the standing, thick forest (tight canopy) that had escaped crown fires in hundreds of years. I saw GP clear cut it, leaving behind a lot of slash and (16″+ dbh) trees downed by the ‘dozers skidding out the logs just to watch them fall. Will a post-burn analysis be done?

    3. “Exploding trees” are shiny objects to shift the public’s concentration from the more relevant issues of this complex phenomenon.

    4. Gotta go for now, but here’s a good YT channel to watch by Jack Cohen. There are several.

  29. Ok, couldn’t let this one go…I have seen many trees explode! The Yellowstone fire in the 80s clearing fire breaks I blew up more trees than I could count. I believe the lay person sees a tree torch and to them the best way to explain it is it exploded. Somewhat like the gas tank on a car, I’ve seen lots of them rupture in giant fireballs, but never seen one actually boom and flip the car over.
    Retired-38 years.

  30. I make mistakes a lot. I like to be corrected–with evidence. When I make a mistake or “misspeak,” I correct or clarify my mistake for the record. I do not take corrections personally.

    The president was perhaps told by some “authority” that trees explode or misinterpreted something he saw on TV. He seems to have a penchant for hyperbole. Where he got the idea that tree trunks lying on the ground exploded is not clear, but nothing burns more slowly than big trunks lying on the ground.

    I grew up in Texas and know the “cedar” trees well (actually they are junipers). The junipers in Arizona “exploded” from a 44 below zero cold snap one year. I have fought fires in Northern California where the North Complex fire is burning now. I surveyed them too. I had a white fir tree burn quickly while I was on the fire line once. I got a free skin peel from the little gobs of pitch it tossed out the top of the convection column. I didn’t feel a shock wave. w

  31. Haha! Is there a big foot? You can believe people that have spent many summers in the forest, fighting fires, or you can believe people that will read a book, or look it up on the internet. Fire management is there for a reason. If tree explosions are an issue, I urge all of you who believe to issue a safe net to your local fire fighting department or your federal supervisor as soon as possible. If they post it and I see it then I will believe that it is true. Don’t take danger as a joke! Take it to your supervisors and make it a known danger or else it will be a myth! Make it known, document, pictures or else it is a myth!

  32. While I can’t say that I was not shocked when I heard Trump say that trees explode about a year and a half after they fall, I can say that I was, somewhat, taken aback. In the years that I have spent roaming the back woods, on the job as a surveyor or simply exploring the outdoors, it would be impossible to count the number of fallen trees I have cut up, climbed over, crawled under, sat on, lay upon, used to cross stream or chasm, even climbed and rode down as they fell the rest of the way to the ground. The vast majority of those trees, in my considered opinion, had been dead for years and even decades. I have never encountered one that has exploded.
    I am not discounting the fact that, in extreme conditions, standing trees have indeed had occasion to detonate explosively. Intense heat and bitter cold are known to have caused this reaction (I’ve seen the videos). That not withstanding, in my 58 years of life I have yet to witness the occurrence or seen the aftermath of a fallen tree, left to its own devices, exploding. This led me to question the validity of the Presidents assertion and thus I have come to this page. Upon reading the article and having perused the commentary (political ideology aside) I have concluded that Mr. Trump spoke in error.
    As it seems others to this forum may still be at odds with a final resolution to this debate I offer but a simple twist to the age old conundrum that may possibly assuage:

    If a tree falls in the forest and there is no one around to drag it away, will it blow up in a year and a half?

    Thank you for your kind attention.
    (well met Bruce Lodge)

  33. Bill, you have a lot of work ahead of you to get the word out on this. I can’t imagine the apocalypse we face if we can’t get President Trump and so many others to stop using the word ‘explode’ in this way: https://www.merriam-webster.com/dictionary/explode%20into%20flames

    https://www.nytimes.com/2020/09/12/climate/oregon-wildfires.html
    “The northwest part of the state, usually much wetter, has dried out this year, enabling flames driven by powerful winds to “just EXPLODE down these canyons.”

    https://www.boston25news.com/news/3-dead-wildfire/2WBDYXMEPSZZFXOAUJAAAJ3FDU/
    “3 dead as wildfire EXPLODES in Northern California”

    https://www.reviewjournal.com/news/nation-and-world/unchecked-wildfires-explode-across-wind-blown-california-2114368/
    “Unchecked wildfires EXPLODE across wind-blown California”

    https://www.timesunion.com/news/article/California-wildfire-explodes-burning-across-25-15555627.php
    “California wildfire EXPLODES, burning across 25 miles in day”

    1. None of what you pasted there says anything about a tree exploding 18 months after the tree falls down, or anytime:

      But with regard to the forest, when trees fall down after a short period of time, about 18 months, they become very dry, they become really like a match stick and they get up you know there’s no more water pouring through and they become very, very they just explode. They can explode.

  34. So…it’s fine to say that a lot of trees “exploded” at the same time, but you can’t express the same concept with reference to a single tree? You can’t see the tree for the forest? As explained by Merriam-Webster, it’s an idiom.

    Keeping his comments in context, even the limited context you just quoted, shows what he meant. He’s not saying the dead and down trees are literal time bombs or some other ordnance. “Like a match stick” they are volatile fuel source that can easily erupt/explode in flames with even a small trigger.

    That’s the most straightforward meaning of his comments. It seems like a big stretch to interpret it differently.

  35. OK. Here’s the deal.

    I first wrote about the myth of trees exploding in 2016 when a senator talked about “trees literally exploding”. I noted then that at least one book and a movie also propagated the myth, and I wanted to dispel it.

    When Mr. Trump said trees can explode, I decided to write a followup to the 2016 article, hoping to clear up any confusion, since trees do not explode.

    Some of the readers of Wildfire Today were offended by what they saw as criticism, and bent over backwards to make what he said seem reasonable. A person might wonder if they would have put up as strong a defense if the same words had been spoken by a different President.

    Bill Gabbert
    Wildfire Today
    Wildfire News & Opinion, since 2008

  36. “Explode” can communicate the behavior of a hand grenade, but it can also be used more figuratively, as the President clearly did when you consider the context in which he used the word. Examples of such figurative language are prolific, especially with reference to fire behavior.

    If you have to write two articles about this, maybe you are the one bending over backwards to force a dubious interpretation of what Mr. Trump said. A person might wonder if they would have put up such a critical effort if the same words had been spoken by a different President.

    Thank you for your articles about wildfires.

    1. Yeah, I think whats getting lost in the translation is the point. Dead trees ought not be left to rot in the forest. They do create the conditions for an explosive fire, a ladder for flames to reach the canopy above. If anyone has doubt about how forest should be managed, you have to ask the experts, Native Americans. YouTube has plenty of educational videos on how they did it. “Tending the wild: cultural burning.” I think this is the point Mr. Trump was trying to make.
      As far as trees exploding, under the right conditions anything could explode. I close my fireplace screen because I know once that log gets preheated, the pressure of the moisture inside is going to explode and send embers out onto the carpet. Its all a matter of interpretation. Have a wonderful day my brothers and stay safe.

  37. I guess I better quit telling people I hauled ass to get here, they might think I carried a donkey on my way. People need to stop taking everything so literal. I’ve never seen wet hay explode into flames either, but put out several that did.

  38. “The most important thing to know is what you don’t know.” –M. Meade

    “The suspension of judgment is the highest exercise in intellectual discipline.” –R. Gilmore

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