# How do the California fires start? **URL:** \ **Category:** Factual Questions\ **Created:** [November 11, 2018, 10:43pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372 "2018-11-11T22:43:20Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [November 13, 2018, 1:06pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/21 "2018-11-13T13:06:39Z")
I remember seeing years ago a satellite study of wild fires on the unmanaged Baja peninsula. (So scrub, not actual forests.) They found a bunch of modest old fire scars of different ages. A fire in older growth would burn for a bit until it the edges of more recent fires where the growth was more modest (no litter buildup) and greener. Then it would stop. (Note also that in these scrubland areas, including S. CA, large, hot fires also affect the soil making runoff higher when the rains come increasing the problems that ensue from that.) Similar patterns also existed in the aspen forests of the Rockies. To get really damaging wildfires you need: 1. Humans suppressing natural wildfires. 2. People building in or near wild areas. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [November 13, 2018, 1:27pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/22 "2018-11-13T13:27:32Z")
I wonder how expensive it would be to cropdust the dry areas with some flame retardant substance (e.g. water) as a preventative measure, rather than just crossing your fingers, hoping for the best, and then dumping a whole bunch of money into cleanup after everything’s been destroyed? ---
**Author:** ![Ulfreida](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ulfreida/32/8014_2.png) [@Ulfreida](https://boards.straightdope.com/u/Ulfreida)\ **Post date:** [November 13, 2018, 1:59pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/23 "2018-11-13T13:59:52Z")
They start when climate changes. California and southern Oregon is a fire ecology, i.e. the plants are adapted and in some cases require fire to pass over them periodically. Native cultures used fire to encourage useful species and suppress others (as is true in other parts of the Americas). When humans caused California to experience longer and longer droughts and hotter and hotter temperatures, small occasional light fires turned to huge inferno fires which now do not pass lightly through, they kill every single living thing. A big factor is all the newly dead timber, also caused by climate change. Drought stress kills trees outright or weakens them so insects kill them. Insects once held in check by cold winters now just keep reproducing. Billions of trees have already succumbed to climate change, west of the Rockies. The worst is yet to come. Believe that. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [November 13, 2018, 2:30pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/24 "2018-11-13T14:30:24Z")
> [@Sage\_Rat](#): > > I wonder how expensive it would be to cropdust the dry areas with some flame retardant substance (e.g. water) as a preventative measure, rather than just crossing your fingers, hoping for the best, and then dumping a whole bunch of money into cleanup after everything’s been destroyed? The scale of the problem really doesn’t allow for that. There is no way to prevent this fuel from burning eventually. You can either have it all at once or repeatedly in smaller doses. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 13, 2018, 2:36pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/25 "2018-11-13T14:36:45Z")
If you mean while adjacent areas are already burning, to try to stop the spread, that’s already standard practice. If you mean to replace the rain, so that the forest never dries out so much that it’ll burn, then you’re basically talking about a very inefficient method of irrigation, over all of the wild space in the West, when California is already straining under the burden of trying to keep the cultivated land irrigated. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [November 13, 2018, 2:49pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/26 "2018-11-13T14:49:53Z")
You could create a grid system of irrigated lines, to split the land into subsections? ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [November 13, 2018, 5:21pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/27 "2018-11-13T17:21:17Z")
> [@Ulfreida](#): > > When humans caused California to experience longer and longer droughts and hotter and hotter temperatures, small occasional light fires turned to huge inferno fires which now do not pass lightly through, they kill every single living thing. Supression is probably the bigger factor, but the native perennial grasses in California where overwhelmed by invasive annual species long ago. In the central valleys, at least, it’s no longer the same plants as when it was only Native Americans there, even in the wild areas. ---
**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\ **Post date:** [November 13, 2018, 7:08pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/28 "2018-11-13T19:08:05Z")
The strong suspicion is that the Camp Fire started from sparking PG&E lines. A property owner right by the ignition site said she got notified by PG&E in an email that they needed to access her property to take care of sparking transmission lines. I read today that PG&E is already up to almost $3 **Billion** in owed damages for fires caused by their transmission lines and/or transformers over the last four years. I wonder how they stay in business. ---
**Author:** ![Rick\_Kitchen](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rick_kitchen/32/522_2.png) [@Rick\_Kitchen](https://boards.straightdope.com/u/Rick_Kitchen)\ **Post date:** [November 13, 2018, 7:29pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/29 "2018-11-13T19:29:41Z")
> [@Sage\_Rat](#): > > You could create a grid system of irrigated lines, to split the land into subsections? In national forests? National forests are expected to be natural. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [November 13, 2018, 7:43pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/30 "2018-11-13T19:43:30Z")
> [@Sage\_Rat](#): > > You could create a grid system of irrigated lines, to split the land into subsections? > [@Rick\_Kitchen](#): > > In national forests? National forests are expected to be natural. National forests are run by the Agriculture department, managed for multiple use including forestry, recreations, resource protection, and wildlife. In principle, they could do something like this and not violate the spirit of the law. But the scale of a project like that is enormous, with a corresponding cost. And it’s fairly useless without water available, as that’s the reason the forests are so dry to begin with. And it would have to be massive in size since 100 MPH winds will carry flames huge distances that a simple water-soaked barrier won’t contain. Bottom line, there’s no economical technical solution to this problem once the forests are in their current state. The only solution we have is to burn the fuel in smaller doses more frequently. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [November 13, 2018, 9:02pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/31 "2018-11-13T21:02:51Z")
> [@DSYoungEsq](#): > > …I read today that PG&E is already up to almost $3 **Billion** in owed damages for fires caused by their transmission lines and/or transformers over the last four years. I wonder how they stay in business. I wonder if they could insulate and bury transmission lines for less than $3 billion. ---
**Author:** ![dorvann](https://avatars.discourse-cdn.com/v4/letter/d/df705f/32.png) [@dorvann](https://boards.straightdope.com/u/dorvann)\ **Post date:** [November 13, 2018, 9:21pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/32 "2018-11-13T21:21:50Z")
I was reading the Wikipedia article on the Great Miramichi Fire of 1825 and it says it burned 16000 square kilometers (6177 square miles) of forest in northern New Brunswick. It also states its among the three largest forest fires ever recorded in North America. Does anyone have any idea what the other two fires would be? [https://en.wikipedia.org/wiki/1825\_Miramichi\_fire](https://en.wikipedia.org/wiki/1825_Miramichi_fire) ---
**Author:** ![Ulfreida](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ulfreida/32/8014_2.png) [@Ulfreida](https://boards.straightdope.com/u/Ulfreida)\ **Post date:** [November 13, 2018, 9:24pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/33 "2018-11-13T21:24:45Z")
> [@DesertDog](#): > > Supression is probably the bigger factor, but the native perennial grasses in California where overwhelmed by invasive annual species long ago. In the central valleys, at least, it’s no longer the same plants as when it was only Native Americans there, even in the wild areas. True of grasslands, which were once much taller perennial grasses which stayed green much longer (the water table was also much, much higher before it was all pumped out). But the replacement annual grasses also come from mediterranean climate zones and hence are also fire adapted. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [November 13, 2018, 9:52pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/34 "2018-11-13T21:52:25Z")
> [@dtilque](#): > > There were a couple very large widfires in Tillamook County, Oregon during the 1930s that gave a lot of impetus to the current practice of suppressing wildfilres. They were called the [Tillamook Burn](https://en.wikipedia.org/wiki/Tillamook_Burn). Holy crap, I remember going to the coast in the late '60s and driving through the damage – more than 20 years after it happened. ---
**Author:** ![SpoilerVirgin](https://avatars.discourse-cdn.com/v4/letter/s/4491bb/32.png) [@SpoilerVirgin](https://boards.straightdope.com/u/SpoilerVirgin)\ **Post date:** [November 13, 2018, 11:24pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/35 "2018-11-13T23:24:16Z")
> [@dorvann](#): > > I was reading the Wikipedia article on the Great Miramichi Fire of 1825 and it says it burned 16000 square kilometers (6177 square miles) of forest in northern New Brunswick. It also states its among the three largest forest fires ever recorded in North America. Does anyone have any idea what the other two fires would be? > > [https://en.wikipedia.org/wiki/1825\_Miramichi\_fire](https://en.wikipedia.org/wiki/1825_Miramichi_fire) Wikipedia has an article listing [notable forest fires](https://en.wikipedia.org/wiki/List_of_wildfires), but if you sort the U.S. and Canada section by size, the Great Miramichi Fire is only #7. Interestingly, the top 7 are all Canadian fires. ---
**Author:** ![sitchensis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sitchensis/32/4892_2.png) [@sitchensis](https://boards.straightdope.com/u/sitchensis)\ **Post date:** [November 13, 2018, 11:40pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/36 "2018-11-13T23:40:48Z")
> [@Telemark](#): > > National forests are run by the Agriculture department, managed for multiple use including forestry, recreations, resource protection, and wildlife. In principle, they could do something like this and not violate the spirit of the law. > > But the scale of a project like that is enormous, with a corresponding cost. And it’s fairly useless without water available, as that’s the reason the forests are so dry to begin with. And it would have to be massive in size since 100 MPH winds will carry flames huge distances that a simple water-soaked barrier won’t contain. > > Bottom line, there’s no economical technical solution to this problem once the forests are in their current state. The only solution we have is to burn the fuel in smaller doses more frequently. If you’re talking about the National Forests then it wouldn’t have to have any cost. It would make money. Fire treatment in the scrubby stuff is where the cost would be. ---
**Author:** ![snowthx](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowthx/32/10660_2.png) [@snowthx](https://boards.straightdope.com/u/snowthx)\ **Post date:** [November 13, 2018, 11:53pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/37 "2018-11-13T23:53:40Z")
> [@sitchensis](#): > > If you’re talking about the National Forests then it wouldn’t have to have any cost. It would make money. Fire treatment in the scrubby stuff is where the cost would be. I don’t know about the making money part, but I think the part about the scrubby stuff is true. That is where the danger lies - with the brush and dead/downed trees that have piled-up for generations. The problems are that there are more people living in these areas than ever before, and those residents do not like the idea of a permanent state of fire treatment going on in their area - people with chainsaws and machinery roaming the woods and causing smoke, year-round. Then there is also the issue of building roads into previously road-less areas to provide access for said machinery, which can cause water quality issues as well as ever-expanding access into pristine areas (e.g. good news for loggers). I don’t know how we restore order to the forests with all this dead fuel piled-up and ready to spark. Maybe just clear a perimeter around communities and hope for the best, and let wild land fires burn themselves out. Of course, when the winds are blowing embers at 60 MPH even a clear space around a town will not stop the spread of the flames. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [November 13, 2018, 11:55pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/38 "2018-11-13T23:55:20Z")
> [@sitchensis](#): > > If you’re talking about the National Forests then it wouldn’t have to have any cost. It would make money. How do you figure? Do you have an estimate of the cost? ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [November 13, 2018, 11:56pm UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/39 "2018-11-13T23:56:10Z")
> [@SpoilerVirgin](#): > > Wikipedia has an article listing [notable forest fires](https://en.wikipedia.org/wiki/List_of_wildfires), but if you sort the U.S. and Canada section by size, the Great Miramichi Fire is only #7. Interestingly, the top 7 are all Canadian fires. But four of those are sets of wildfires, rather than single fires. The Great fire of 1919 and the Chinchaga Fire are the single fires listed there which are larger than the Miramichi fire (According to that list - estimates for older fires may not be that accurate. Note that they list the Chinchaga fire (1950) as the largest “on record”). The Carr fire, and the current Camp Fire are nowhere near those in size, in spite of the damage and deaths they’re causing. The crucial point is their proximity to inhabited areas. ---
**Author:** ![sitchensis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sitchensis/32/4892_2.png) [@sitchensis](https://boards.straightdope.com/u/sitchensis)\ **Post date:** [November 14, 2018, 12:28am UTC](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372/40 "2018-11-14T00:28:11Z")
> [@Telemark](#): > > How do you figure? Do you have an estimate of the cost? I could work up some better numbers but off the cuff. Average value for the wood would be $400 per thousand board feet (mbf). Subtract out $120 per mbf “stump to truck” cost and another $125 per mbf for hauling. $40 per mbf for profit and risk. That leaves a residual value for the landowner of $115 per mbf. With an average per acre volume of 20 mbf, that calculates out to $2300 per acre in profit to clearcut. If we chose to do a selective cut and say remove 50% of the basal area based on the current or historical diameter classes and come up with a prescription that includes leaving most dominants as legacy trees. We would be well on our way to creating the types of horizontal and vertical structure that’s valued as old growth while making around $1000 per acre. [Previous page](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372.md?page=1) [Next page](https://boards.straightdope.com/t/how-do-the-california-fires-start/824372.md?page=3)