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The Firestorm This Time: Why Los Angeles Is Burning (wired.com)

The Thomas Fire spread through the hills above Ventura, in the northern greater Los Angeles megalopolis, with the speed of a hurricane. Driven by 50 mph Santa Ana winds -- bone-dry katabatic air moving at freeway speeds out of the Mojave desert -- the fire transformed overnight from a 5,000-acre burn in a charming chaparral-lined canyon to an inferno the size of Orlando, Florida, that only stopped spreading because it reached the Pacific. Several readers have shared a Wired report: Tens of thousands of people evacuated their homes in Ventura; 150 buildings burned and thousands more along the hillside and into downtown are threatened. That isn't the only part of Southern California on fire. The hills above Valencia, where Interstate 5 drops down out of the hills into the city, are burning. Same for a hillside of the San Gabriel Mountains, overlooking the San Fernando Valley. And the same, too, near the Mount Wilson Observatory, and on a hillside overlooking Interstate 405 -- the flames in view of the Getty Center and destroying homes in the rich-people neighborhoods of Bel-Air and Holmby Hills. And it's all horribly normal. [...] Before humans, wildfires happened maybe once or twice a century, long enough for fire-adapted plant species like chapparal to build up a bank of seeds that could come back after a burn. Now, with fires more frequent, native plants can't keep up. Exotic weeds take root. Fires don't burn like this in Northern California. That's one of the things that makes the island on the land an island. Most wildfires in the Sierra Nevadas and northern boreal forests are slower, smaller, and more easily put out, relative to the south. Trees buffer the wind and burn less easily than undergrowth. Keeley says northern mountains and forests are "flammability-limited ecosystems," where fires only get big if the climate allows it -- higher temperatures and dryer conditions providing more fuel. Climate change makes fires there more frequent and more severe.

22 of 231 comments (clear)

  1. Here come those Santa Ana winds again by rmdingler · · Score: 4, Interesting
    There are ideal conditions for wildfires in this region (and others) nearly every year. What's special about this year?

    "What we don’t have every single year is an ignition during a wind event. And we’ve had several."

    Whether by foolish acts or (pyro)maniacal disposition, people are the blight on this land.

    --
    Happiness in intelligent people is the rarest thing I know.

    Ernest Hemingway

    1. Re: Here come those Santa Ana winds again by Opportunist · · Score: 3, Insightful

      That must be the reason those hurricanes predominately devastate the Bible Belt, I guess?

      --
      We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
    2. Re: Here come those Santa Ana winds again by rmdingler · · Score: 5, Insightful

      The application of God's will to a particular event is rather arbitrary. He gets credit for a lot of touchdowns, yet blamed for very few fumbles.

      --
      Happiness in intelligent people is the rarest thing I know.

      Ernest Hemingway

    3. Re: Here come those Santa Ana winds again by Opportunist · · Score: 4, Funny

      So ... God is a CEO?

      --
      We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
  2. Re:The priesthood has spoken by Opportunist · · Score: 4, Insightful

    Nobody keeps you from giving us a better explanation for the increasing number and severity of natural disasters.

    We're waiting.

    --
    We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
  3. True by 110010001000 · · Score: 3, Funny

    There were never wildfires before climate change was discovered.

    1. Re:True by Gravis+Zero · · Score: 4, Interesting

      There were never wildfires before climate change was discovered.

      The is real problem is that we're been putting out the wildfires for over a hundred years when burning is part of the natural cycle of life for the ecosystem. As a result there are many millions of dead and dry trees just waiting for a spark. However, climate change is exacerbating the issue by causing more extreme weather (longer droughts and more extreme downpours) which ultimately kill more plants and turn them into fuel for the fire. Climate change definitely isn't the cause of these giant wildfires but it is making it worse.

      --
      Anons need not reply. Questions end with a question mark.
  4. Dontcha need wetter for more fuel? by xxxJonBoyxxx · · Score: 3, Interesting

    >> higher temperatures and dryer conditions providing more fuel

    I thought you needed WETTER conditions to get more fuel. Is anyone surprised that there are a bunch of large fires after California's water supply returned to normal and plants had a chance to grow back? (It was as green along Hwy 1 as I've ever seen it this year.) That stuff dries out...and then burns - science, yo.

    http://www.mercurynews.com/2017/10/03/will-this-winter-in-california-be-wet-or-dry/

    1. Re:Dontcha need wetter for more fuel? by dfm3 · · Score: 4, Interesting

      TFA does a better job than the summary at explaining, but yes, your observation is consistent. Wetter summers mean more vegetation growth, but it's the weather during a few critical weeks in late fall that determine how severe the fires will be.

      It's the small stuff (leaves, brush, and weeds) that burns fast, hot, and explosively given the right conditions. In the fall, when the deciduous species lose their leaves, a wet December means that most of this vegetation falls to the ground and begins to decompose, rendering it more dense and less flammable. When you have a combination of dry weather, warm temperatures, and high wind, combined with ignition (historically caused by lightning, but usually by people these days), leaves tend to stay on the trees longer, or fall to the ground without decomposing, and become perfect fuel.

      So yes, you're correct that when this stuff dries out, it becomes a hazard.

      For example, last fall was a historically notable fire season in the southern Appalachians. Many parts of the mountains in NC/TN/GA had little to no measurable rainfall for a couple months, so the leaves simply dried up and stayed on the trees rather than changing color and falling to the ground. The deadly fires that swept through Gatlinburg, Tennessee became "canopy" fires - an event more common in California but virtually unheard of in eastern forests. Even one good rainstorm could, in theory, have been sufficient to knock enough leaves off of the trees and compress the leaf litter on the forest floor to render it slightly less flammable.

  5. Re:The priesthood has spoken by Anonymous Coward · · Score: 5, Insightful

    Your assumption that natural disasters are getting worse is false. The "cost of damages" is rising because of increased construction in hazard areas and more expensive construction in those areas.

    If you look at hurricane tracking, you'll find a sharp jump in the record a few decades ago. This came from the start of off-shore counting. Before that, only storms that made landfall as a hurricane were counted. This invalidates many claims of worse storms.

    Earthquakes of significance are unchanged. Despite panic that small rock-settling after fracking would result in new faultlines exploding (or whatever nonsense those stories got to).

    Wildfires happen regularly in nature. The article is nonsense about their rarity. Wildfires of this size occur only if there is an abundance of fuel. Naturally, that requires a drought after a couple decades of being too wet to burn. Thanks to California fire departments, all the small wildfires that would've cleaned out the accumulating fuel were extinguished before they could consume much dead wood.

    Volcanos are still erupting within the wide range of statistical uncertainty.

    I know this is the part where you log onto one of your sockpuppets and moderate me down for actually answering your dogma, and maybe post a [citation needed] or ad-hominem attack to dismiss my explanations without any further thought on your part.

  6. Re:The priesthood has spoken by tsqr · · Score: 5, Insightful

    Nobody keeps you from giving us a better explanation for the increasing number and severity of natural disasters.

    We're waiting.

    I'm a SoCal native; been living here over 0x3C years. Low humidity and high winds show up at the same time during Santa Ana events, and it happens every year. Brushfires occur so regularly that an autumn without at least one bad one is pretty rare. Maybe the reason they look like they're getting worse (causing more destruction) is that more more people are moving into fire-prone areas.

  7. Re:The priesthood has spoken by Opportunist · · Score: 3, Interesting

    I have no sockpuppets, I'm actually happy I got an answer for a change. Thank you.

    The arguments sound valid so far, I'll have to look into it.

    --
    We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
  8. Re:The priesthood has spoken by Bing+Tsher+E · · Score: 5, Insightful

    When the population increases in an area, people are always driven to build more housing on the bad land. It's no surprise when 'expensive new housing' is flooded or beset upon by a hurricane. The 'bad land' is the places where there aren't already 100 year old structures.

  9. Re:The priesthood has spoken by cyberchondriac · · Score: 5, Funny

    I have no sockpuppets, I'm actually happy I got an answer for a change. Thank you.

    The arguments sound valid so far, I'll have to look into it.

    Where is Slashdot and what have you done with it?!? ;)

    --

    Look back up at my post, now look back down, you're on the Internet. Now look back up. I'm a signature.
  10. Re:The priesthood has spoken by bobbied · · Score: 5, Insightful

    Nobody keeps you from giving us a better explanation for the increasing number and severity of natural disasters.

    We're waiting.

    Because... We put fires out and restrict landscaping practices that would otherwise reduce the available fuel so when fires do happen, they are more intense and do more damage than they used to.

    We discovered this in the nation's national forests. Where for decades we kept putting out fires, even small ones, that naturally cleared out the brush and growth on the ground. This brush grew bigger, creating huge fuel loads that was getting stacked up at the base of mature trees. Finally, a uncontrollable fire would happen and because of all the fuel that collected would burn hotter and faster. Where the mature trees used to survive the smaller more frequent fires, the less frequent hotter fires was enough to kill them. The solution was to either clear the brush manually, or let the fires burn more often.

    In LA, the issue is not that fires happen more often, but that they happen LESS often and more fuel piles up. Then when the hot/dry conditions come on those windy days then the whole mess of kindling will be impossible to put out, burn hotter, faster and more deeply. Then like idiots, we build houses next to all this and try to make excuses for why we cannot keep them from burring down every so often.

    Yea, man caused this mess, but not the way you think.

    --
    "File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
  11. Re:The priesthood has spoken by bobbied · · Score: 3, Interesting

    Also, don't forget that humans have been putting out fires in these areas for decades. Fire is a natural part of this ecosystem and we put them out and restrict land management practices that would have reduced the available fuel in these areas currently burning. In that way we HAVE made these particular fires worse. So, I don't think we can lay the whole blame here on Global Warming... Even if it fits the accepted narrative... Some blame? Maybe a very small part of the hot/dry weather, but this is hardly provable. LA is a hot dry and windy place this time of year and always has been in our recorded history.

    --
    "File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
  12. Same Thing as Every California Wildfire by eepok · · Score: 3, Interesting

    Every big stretch of wildfires are caused by the same thing:

    1. High winds
    2. Low humidity
    3. Unmanaged brush
    4. Either a lightning storm or (more likely) some human doing something stupid (camp/bonfire, trash burning, arson, cigarette, etc.)

    This year was particularly bad for both Northern and Southern California because this past winter's rain was so significant that it almost completely erased the multi-year drought. That means lots and lots of greenery growing in the spring and waiting to burn throughout the summer and fall.

  13. Left out the other stuff. by gurps_npc · · Score: 3, Informative

    1) We have been ignoring the fire risk for a long time. Specifically we have stopped all small fires before they get anywhere, which means there are a lot fuel wood stocked up. The smarter thing to do is to let small fires become controlled medium sized fires during the WET season, rather than the dry season when they become huge.

    2) We have been putting houses in stupid locations and not requiring appropriate fire prevention measures. There is nothing wrong with building a house in the middle of fire zones. But make it a bunker out of concrete. Yes, it won't look the same as a normal house, so freaking what? A good architect can make a concrete, fire-proof home still look good. Yes it costs more. But less than double, which is what most people will pay.

    3) Oh yeah, and stop counting fire smoke from intentionally set preventative fires as 'pollution' while saying that smoke from natural forest fires doesn't count because it isn't man made.

    --
    excitingthingstodo.blogspot.com
    1. Re: Left out the other stuff. by Miamicanes · · Score: 3

      If the current fires encountered a large expanse of concrete devoid of anything directly combustible, how wide would it have to be to actually stop the fire's spread?

      As I understand it, once uncontrolled outdoor fires reach a certain size, they act kind of like weak tornadoes that lift flaming objects high into the air & hurl them out to areas that might be several thousand feet away (enabling the fire to jump over thing like freeways, canals, etc).

      If a house in the middle of an affected neighborhood had reinforced concrete walls & roof, plus Miami-grade impact-glass windows, would the heat of the fire as it burned down the neighbors' houses cause the concrete house's interior to combust anyway (like food debris in a self-cleaning oven)? Would ICF construction plus roll-down steel shutters keep the interior cooler, or would the intense heat just cause the ICF styrofoam itself to melt or combust?

      I know that conventional wisdom is that individual homeowners are helpless against a fire, but I remember reading about one guy in California a few years ago who put sprinklers on his roof & surrounding yard, connected them to the faucet, and left it running when he evacuated. When he got home, his home had major "baking" damage... but his neighbors' homes were literally burned down to the scorched earth. I think some local official later decided to be a dick & fined him $10,000 for violating water-conservation rules to discourage others from trying to do it in the future.

  14. Re:The priesthood has spoken by PPH · · Score: 3, Insightful

    A lot of the fire problem has to do with the sorts of people moving onto the land. In the past, land like this would probably have been used as ranch land. And the people responsible for it would have allowed fires to burn through it occasionally. Now, it's the hipsters. And just look at all that beautiful desert scrub growing right up to my back door!

    We have the same problem (to a lesser degree due to rainfall) where I live. We used to clear brush annually and burn it. But now the eco-whackos have put a stop to that. So be prepared for a ten year cycle of fire ripping through the canyon, burning all your houses to the ground.

    --
    Have gnu, will travel.
  15. Re:The priesthood has spoken by judoguy · · Score: 3, Interesting

    When the population increases in an area, people are always driven to build more housing on the bad land. It's no surprise when 'expensive new housing' is flooded or beset upon by a hurricane. The 'bad land' is the places where there aren't already 100 year old structures.

    Upvote, upvote, upvote.

    I grew up going to NC outer banks for holidays. The Styrofoam stucco houses on the beach regularly get devastated while some of the first structures built are still there. People in the 1600's and 1700's knew about the ocean and weather and built as high up as possible and as far from the beach as feasible.

    --
    Peace is easy to achieve, just surrender. Liberty is much harder get/keep.
  16. Re:The priesthood has spoken by rrohbeck · · Score: 3, Insightful

    Munich Re has a chart with weather/flood related insurance claims versus other (usually geophysical like earthquakes.) The first category has increased 4x relative to the second over the last few decades.