Some climate activists and media outlets are claiming the drought or climate change were major contributors to the recent wildfires around Los Angeles (see sample below)
These claims can easily be shown to be false.
Long-term Drought had little impact on the LA fires.
Climate Change had little impact.
The vegetative fuels for the fires were predominantly light fuels such as grasses and range vegetation. To illustrate, consider the area where the Palisades fire started (below).
Most of these fuels are 1-10 hr fuels, which means they typically dry out after 1-10 hours of drying conditions.
The meteorological conditions immediately preceding the fires were so drying (very strong winds with very low humidities) that even if it had rained the week before, the fire still would have occurred.
Consider a plot of the ten-hour fuel moisture at the nearby Topanga Canyon site over the past year (below). Keep in mind that when the moisture level gets below 15% rapid fire spread is possible.
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There is No Trend for Less Precipitation in Southern California
Several media and other outlets suggested climate change associated dry conditions was a contributor to the LA wildfires. First, as noted above, the light fuels that brought the fires to the homes did not need a drought period to be sufficiently dried to burn.
But even if drought had been important, there is no evidence than climate change could have contributed. How can I be be so sure? Because there is no long-term trend for less precipitation over the region.
Consider the trends of October 1 to January 6 precipitation at Los Angeles from 1950 through this year (see below). The trend line is UPWARDS (brown line). More rain, not less. Yes, the past autumn was dry, but that is not climate but normal weather variability.
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It makes complete sense that global warming would weaken the Santa Ana winds.
Such winds are driven by difference in pressure between inland high pressure and lower pressure to the south and west. This high pressure is associated with low-level cool air (cool air is denser and heavier than warm air), which will be warmed due to global warming, thus reducing the pressure difference that drives the Santa Ana winds.
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Very strong video and photographic evidence indicated the Los Angeles Eaton fire, which resulted in the most deaths was due to a faulty power line. Clearly, this transmission line was not de-energized even with the forecast of severe Santa Ana winds.
The truth can be difficult to grapple with, so people prefer life experiences be explained away with simple clichés. The climate change cliché provides the easy out.
ReplyDeleteAm seeing this used many times a day in articles written about this fire.
DeleteGreat point Cliff especially on poorly designed homes as it relates fire fire-resistant materials and design. This article highlights that https://headwaterseconomics.org/natural-hazards/wildfire-resistant-costs-california/?utm_source=chatgpt.com
ReplyDeleteBe nice if they could send us some of the wind. I'd like to trade this tule fog for some sunshine.
ReplyDeleteOk, so no climate change attribution for how dry it is or the low current humidity. But could you please address the wind speeds observed (both sustained and gusts) and how/if they are related to climate change? Might as well comment on Lahaina if you can at the same time. Anyone older than 40 years old can casually observe that these events seem to be getting worse.
ReplyDeleteAre adverse weather events in southern California actually getting more frequent and more intense? Or is it actually the case that more and more people are moving into SoCal areas which have always had serious wildfire hazards associated them -- hazards which state and local authorities have decided are less important to deal with than are other kinds of environmental, social grievance, and social spending priorities.
Delete1) per Cliff "There is an extensive peer-reviewed science literature indicating that global warming will reduce the strength, intensity, and frequency of such Santa Ana winds"
Delete2) Human perception is highly flawed - ie, when you're shopping for a Volkswagen every car seems to be a Volkswagen
3) Even IF fires are getting worse it could be due to any number of reasons, including fire prevention/management (clearing brush, less logging roads, water management, etc), increased population (as a result of immigration) or any number of other reasons.
As someone over 40, I can tell you I cannot make that statement. Worse by what means? Actual wind speeds? We cannot just say since we are over 40 we've seen it all. If stating we are seeing more destruction of property and dollar loss, look beyond the weather to answer that question. It's not the fact that things have gotten any worse, it's the fact we are building more in areas that suffer from these events. More people, more houses, more the loss of life and destruction. But again to say a person can observe its getting worse is to assume that you've seen everything mother nature has to offer within our short lives. Cliff has again and again proven our perceived severity of events do not play out in the actual numbers or trends.
DeleteI have lived in SoCal for 60+ years. The Santa Anas we remember from childhood are the ones in September that pushed daytime temps to 110F and kept nighttime lows over 80F. There has not been a nighttime Los Angeles low over 80F since 1988. The continental "low-level cool air (cool air is denser and heavier than warm air), which will be warmed due to global warming" doesn't happen in September any more. I do not believe midwinter Santa Ana incidence has changed since I was a kid. But removing September from Santa Ana season is surely a reduction in overall fire risk.
DeleteFWIW, I lived in LA in the early 90s and Santa Ana winds gusts were never more than 40MPH. 90-100MPH gusts seems to be a recent phenomenon.
ReplyDeleteJay...there are plenty of other examples of Santa Ana winds as strong or stronger..cliff
DeleteHere’s a story about a local-to-Altadena weather enthusiast who pre-warned the community of the extreme fire danger and helped save a bunch of lives.
ReplyDeletehttps://www.goodnewsnetwork.org/hundreds-credit-altadena-heros-early-weather-predictions-for-saving-them-from-the-eaton-fire/
Cliff: Facts are difficult for many people to understand. They prefer opinions, "my truth" and "science model predictions". Keep putting out the facts. We all hope that science education and information will overcome ignorance, prejudice and political silliness. Keep going. In wonder if the political climate changes, and improves, will global climate improve and tipping points and disaster scenarios become less certain in the "free press"?
ReplyDeleteCliff, LA Mayor stated "firefighter have never seen winds this fierce." But one could simply google and 2011 saw the strongest winds from the Santa Ana winds with sustained 97mph and gusts 167mph. Could you provide more too wind events. Think it is crucial that people know her and other over statements don't do any good. Stating it's the worse I've ever seen doesn't fix it nor make it better. It leads people on a path to do stuff or spend resources on things that won't help.
ReplyDeleteWhile the overall precipitation trend may be upward, it also looks more volatile (bigger more regular swings between very wet and very dry), which is really the thing that makes this so dangerous.
ReplyDeleteAlso, how much of the fires were grass fires versus tree/shrub fires, particularly the vegetation/landscaping around houses? From what I've seen it's definitely not just grass, but lots of (probably very dry at this point) larger plants.
Look at the data I showed. There is no evidence of precipitation becoming more volatile. And the light fuels were the critical transport media of the fires. Vegetation around homes is irrigated.
DeleteThe Santa Ynez reservoir was taken offline by a department of the city of Los Angeles that provides power and water. It apparently didn’t relate that information to the fire department at a high level for planning purposes. I can’t imagine that the local fire station was not aware. Their concerns may have been ignored. What’s even more astonishing is that the reservoir improvement project has been going on for 21 years. I have located an online document, of 105 pages, that dates back to 2003, and that states that the reservoir renovation and covering project will have no significant impact on fire responses. Oops.
DeleteHere’s the critical paragraph in the EIS, page 39:
“XIII. PUBLIC SERVICES
a) Result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services:
i) Fire protection?
Less Than Significant Impact. Construction of the proposed project would occur within the existing reservoir site, away from the road system.
Therefore, the construction of the proposed project is not anticipated to reduce access for emergency vehicles near the project site. During construction, the existing reservoir would be drained of all water, thus reducing the available supply of surface water for fighting fires (i.e., for use by firefighting helicopters) in the local area, which may potentially increase risks to people or structures from wildland fires. However, the existing fire hydrant located on the site is supplied by a pump located at Palisades Drive and would not be affected by the proposed project. In addition, other surface water sources exist in the vicinity of the proposed project site (e.g., Pacific Palisades Reservoir [approximately 3 miles east of Santa Ynez Reservoir] and Santa Ynez Lake [approximately 2 miles south of Santa Ynez Reservoir]) that could be utilized for firefighting purposes in the event of a wildland fire during construction activities. Operation of the proposed project would occur at the existing reservoir facility and would not require additional fire protection. Impacts relative to fire services would be less than significant and no mitigation is required.“
Here’s the source: https://www.ladwp.com/sites/default/files/documents/Santa_Ynez_Reservoir_Initial_Study_MND.pdf
DeleteIn the California chaparral, chamise is one of the main fire carriers. It is an evergreen, drought-tolerant, resinous and fire adapted. While the fuel moisture of the 1 and 10 hour fuels (dead fuels) may not be impacted by the current drought, the current live fuel moisture of chamise in the LA basin is in the high 50s and low 60s percentiles. That's critically low. Per LA County Fire Dept charts, the normal percentile for this time of year is well over 100%. It would be interesting to know 1) current drought impact on live fuel moisture, and 2) contribution of live fuels to the experienced rates of spread and intensity.
ReplyDeleteCheck out the paper "Critical live fuel moisture in chaparral ecosystems: a threshold for fire activity and its relationship to antecedent precipitation" (Dennison and Moritz 2009), which found an ~79% LFM threshold bellow which large fires become significantly more likely. This threshold is reached over the course of several dry months following a rainy period.
DeleteThis is presumably why the fire season in Southern California does not typically extend into winter despite Santa Ana winds being common throughout the season (they peak in December). The lack of meaningful rain so far this season was almost certainly an important factor in setting the conditions for these fires.
I grew up in northeast Pasadena, in the Upper Hastings Ranch neighborhood. That neighborhood is the foothills of the San Gabriel Mountains. The Eaton fire has wiped out many of those homes, not more than two blocks from my boyhood home.
ReplyDeleteWildfires are endemic to Southern California. The wildfire pattern is:
Santa Ana winds and a fire source start a fire.
The fire burns away all the brush that's accumulated since the last fire.
The rains come and cause mudslides.
The brush resproots. More rain, more brush.
Rinse and repeat.
The incompetents of LA and CA were more concerned with endangered species and identity than protecting the people of LA. A powerpole replacement project in Topanga Canyon was shutdown to protect a brush species. The Santa Ynez reservoir (117 million gallons) was drained because of damage to its cover. The Sacramento Delta Smelt is more important than water storage. The mayor of LA is more concerned with hiring the right checkboxes than hiring ompetent people.
The Democrat politicians turned the normal wildfire season into a catastrophic wildfire season. Karen Bass and Gavin Newsome will soon be hitting the unemployment offices.
Many homes burned from the inside out from embers that entered through unscreened openings in eaves and soffitts. This ignition source could have easily been prevented.
ReplyDeleteYes if people would have just cleaned out their gutters, the fire would have been stopped right in it's tracks. OK...
DeleteIt's very dubious to be saying that all the fuel for these fires was grass. A lot of these areas are chaparral which is actually thick shrubbery and small trees without much grass.
ReplyDeleteall the fuels are not grass. No one has said this The grass fire led to heavier vegetation burning as well. Even a wet log will eventually burn....as I learned frequently in real life....cliff
Delete"wet logs will burn"?? Yeah but it's the dry ones that cause big fires and it takes a lot longer for them to dry:
DeleteObserved Impacts of Anthropogenic Climate Change
on Wildfire in California, AGU 2019EF001210, Columbia U/UCLA/U of Idaho/U of Colorado/Scripps Fig2 FM1000 vs Acres Burned CA 1972-2018 QED
Once it entered the neighborhoods a lot of the fuel were the houses themselves. You would see the same widespread destruction in any neighborhood in the US with 100mph winds
DeleteSpeaking of fires in California, a huge lithium battery fire is now raging at the Vistra Energy battery storage facility in Moss Landing, one of the largest such facilities in the world.
ReplyDeleteAs is now being reported, the blaze, which erupted late Thursday afternoon, has sent plumes of hazardous black smoke into the air, prompting evacuations, road closures, and a significant emergency response effort.
Massive Fire Engulfs Moss Landing Battery Plant, Triggers Evacuations
OK, what is happening here in Washington state concerning large-scale battery storage facilities which should be of concern to us?
The huge Horse Heaven Hills 750 MW wind/solar/battery farm recently approved by Washington State’s energy siting board is now being built fifty miles west of where I live here in the Middle of Nowhere, southeastern Washington.
South of the Horse Heaven Hills in northeastern Oregon is the Umatilla Army Depot where poison gas munitions and nerve agents had been stored for a number of years prior to the year 2000.
A billion-dollar chemical waste disposal plant was built onsite in the early 2000’s to burn all these chemical weapon materials. The Army's campaign to dispose of those materials ran for a decade between 2002 and 2012.
Emergency response personnel in Oregon and Washington communities within a fifty-mile radius surrounding the Umatilla Army Depot had to be trained and equipped to deal with any chemical release events which might occur while the Army’s decade-long chemical munitions disposal campaign was in progress.
As far as I am personally aware, no steps whatsoever are now being taken by local communities in those Oregon and Washington communities within a fifty mile radius of the Horse Heaven Hills wind/solar/battery farm to deal with a future battery fire and toxic chemical release which might occur at this new facility.
As always, excellent analysis from Cliff Mass! Thanks!
ReplyDelete