Colorado’s Marshall Fire: Has Funding Needs Corrupted Climate Science?

 

I was totally shocked to hear the claims by a fire scientist I had once admired and often quoted in my blog posts about wildfire. 

In a National Public Radio interview Jennifer Balch said, “Climate change has lengthened the state's fire season”. Then she said “"Climate change is essentially keeping our fuels drier longer. These grasses that were burning, they've been baked all fall and all winter.” 

 Having studied fire ecology for 30 years and knowing her published science, I could only believe she had been corrupted by the need to attract large amounts of funding, and these days that comes to those who blame the climate crisis. And here’s why I now hold that opinion so strongly. 

Colorado’s Marshall Fire was a grassfire that happened with temperatures hovering around freezing. All fire experts and fire managers know grasses are 1-hour lag fuels. That means in dry conditions grasses can become flammable within hours. Attempting to link CO2 global warming, she and other alarmists were now blaming the Boulder area’s grass flammability on the warm dry conditions from July through November. But dry conditions in the past months are totally irrelevant. Those months could have also been cold and wet, but just one day of dry conditions is all that is needed for grasses to burn. 

To minimize recklessly set fire that often occur as people burn away unwanted dead vegetation, the Nova Scotia government felt the need to counter the misunderstanding writing:

The Myth:  “It's safe to burn grass as long as there is still some snow on the ground.” 

The Fact: “Within hours of snow melting, dead grass becomes flammable, especially if there have been drying winds. Grass fires burn hot and fast and spread quickly around, and even over, patches of snow.” 

That’s a fact that Balch and every other fire expert should know! Apparently, Daniel Swain, a climate scientist at the University of California Los Angeles and the Nature Conservancy and acolyte of climate alarmist Michael Mann and Noah Diffenbaugh, also failed to understand grasses are 1-hour fuel.  He stated in an interview for NBC’s article How climate change primed Colorado for a rare December wildfire that “Climate change is clearly making the pre-conditions for wildfires worse a cross most fire-prone regions of the world,” 

But dry grasses are not the pre-condition to be worried about. The pre-conditions that neither Swain nor Balch shared with the public is well known: Boulder County’s invasive grasses increase fire danger. The “main offender is cheatgrass, which was likely introduced to the area alongside agriculture and ranching” and “is increasing fire danger by 29%” 

 In fact, in 2013 Balch published, Introduced annual grass increases regional fire activity across the arid western USA (1980–2009), writing “Cheatgrass was disproportionately represented in the largest fires, comprising 24% of the land area of the 50 largest fires” and that “multi-date fires that burned across multiple vegetation types were significantly more likely to have started in cheatgrass.” 

 It was also very disingenuous for Balch to say ““Climate change has lengthened the state's fire season”. It is the very same meme that every climate alarmist regurgitates that climate change has made “a year-long fire season the new normal”. But in 2017 Balch published in Human-started wildfires expand the fire niche across the United States that human ignitions “have vastly expanded the spatial and seasonal “fire niche” in the coterminous United States, accounting for 84% of all wildfires”. 

Balch’s published graph clearly shows that human ignitions have extended fire season all year long. Based on her own research, a more relevant comment would have mentioned that Louisville, Colorado’s population had jumped 10-fold; from 2,000 in 1950 to about 20,000 today. Does a 10-fold increase in population create a 10-fold increase in fire probability. The Marshall Fire was not naturally started by Lightning. 

In 2015, Balch created the Earth Lab program at Colorado University. In 2017 it became part of CIRES, a partnership of NOAA and CU Boulder. Earth Lab, got increasing attention from mass media that’s always seeking click-bait. As Earth Lab’s team began blaming more fires on climate change, it got more attention and Balch got more interviews. 

 Earth Lab hired Natasha Stavros as Earth Lab’s Analytics Hub Director. In videos posted by the Washington Post, she claimed climate change causes “longer, hotter, and drier fire seasons” reflecting Balch’s conversion to a climate crisis narrative. To get around Balch’s earlier scientific research Stavros deflected, “We are not talking about the ignition source” or the “availability of fuels”, “what we are talking about are the conditions of those fuels”. But in the case of the Marshall Fire, 1-hour grass fuels have nothing to do with climate change. It only takes a few hours to be in highly flammable conditions. That’s weather, not climate! 

 Although lacking in scientific integrity, pivoting to a climate crisis narrative worked in Balch’s favor. The U.S. Geological Survey has selected the University of Colorado Boulder to host the North Central Climate Adaptation Science Center (NCCASC) for the next five years. Balch, as director of CIRES’ Earth Lab, and now NCCASC Director had attracted $4.5 million in funding. Universities around the country similarly create such centers to attract such major funding. Certainly, blaming fires on a climate crisis attracts more funding than if its director sounded like a “denier” blaming invasive grasses and human ignitions. 

 The politics of funding research requires a major level of group think. Daniel Shechtman won the Nobel Prize for discovering quasi-crystals that are now used in surgical instruments. But when he first announced his observations, he was kicked out of his lab by his colleagues. They saw him as a threat to the lab’s prestige and funding because observing quasi-crystals contradicted the consensus that was enforced by Linus Pauling that quasi-crystal did NOT exist. 

 Similarly, esteemed atmospheric scientist Dr Cliff Mass was criticized by Washington University administrator’s for detailing how an episode of problematic acidic waters that had been pumped into the state’s oyster’s hatcheries, was due to natural upwelling events, not climate change. But contradicting the climate crisis angle threatened funding to WU’s Ocean Acidification Center. Up until then Mass had been the Seattle Times go-to person for all weather events, but that stopped when his one analysis didn’t support climate crisis groupthink. Dr Peter Ridd was fired for presenting evidence showing his colleague's claims of coral reef destruction were exaggerated. So, all savvy university professors know you can’t contradict the meme if you want funding, or worse, keep your job. 

 Climate crisis groupthink, also ignores natural climate change, as did Balch and Swain. But one meteorologist confidently blamed the lack of snow and dryness on a natural La Nina. The science is well established that depending on how colder Pacific surface waters set up during a La Nina, atmospheric currents can carry higher or lower amounts of moisture to different regions. California had record snowfall this December while Colorado snowfall was very low. And if the Marshall Fire had been ignited just 2 days later, there would have been a snowfall to suppress the fire.

However too often, alarmists scientists cherry-pick one-year events. They weaponized this year’s low snowfall while ignoring that last year’s Colorado snowfall was far above normal. In November last year, Fort Collins received more than 15 inches of snow on its way to 80 inches, which is 25 inches more than normal. Again, such variations in snowfall are weather, not climate. 

Alarmists also weaponized the dry conditions as solely due to global warming drought. They ignored the drying and warming effects of the Chinook winds that are very common in Colorado. Chinooks are known as “snow eaters” because as the winds pass over the mountains of the western USA they are forced upward and precipitate all their moisture. When those winds descend from the Rockies down to Boulder, temperatures rise adiabatically (due to pressure not added heat) and the warm dry air quickly removes moisture or snow from the surface. Southern California’s Santa Anna winds are similar and drive large fires. 

Sometimes Boulder’s winds reach speeds of 100+ mile per hour. NOAA reported The Chinook Wind Events Winter of 1982 during which peak wind gusts more than 100 mph damaged areas around Boulder. Weatherwise journal reported 100+MPH winds over Boulder on January 7, 1969, which snapped power poles and toppled planes as seen in the photographs below. In November 2021 the weather service gave a red flag warming due to the high winds from a Chinook event. But without a coinciding human ignition, there was no rapidly spreading fire.

 

I would like to believe that Balch’s Earth Lab scientists have been campaigning for the housing developments in Boulder’s suburbs of Louisville and Superior to create a system of firebreaks and defensible space. Those suburbs had built into easily ignited grassland in a region where fires are rapidly spread by the dry Chinooks descending from the Rockies. Such natural fire danger is not always obvious to the public looking for affordable housing. But it is not obvious that was ever done, at least not as obvious as faulty climate change narratives. 

 Fire experts should have pushed for building codes, requiring adequate spacing between new houses. As a story in Wildfire Today reported today, one common feature of the surviving homes was they were more distant from neighboring homes. Many houses in the devastated subdivisions were only 10 to 20 feet apart. Without adequate fire breaks or defensible space, if just one house allowed the fire to reach it, the heat of that burning house is enough to ignite any house next to it. Similar dynamics were seen in California’s Tubbs and Camp Fires that demolished neighborhoods.

 

But perhaps local governments were greedy. Eager to build a tax base a growing Louisville population was most important. Politicians had worked hard to present Louisville as one of the top 10 most livable little cities. Putting natural fire danger front and center, might put a damper on the city’s attractiveness. And not surprisingly the Denver Democrats didn’t waste time to capitalize on the Marshall Fire devastation. The released a statement claiming “This fire has also punctuated our climate crisis and made abundantly clear the need for bold action. The science is clear, and the impacts are very real. We will continue to work with our community and legislators to ensure climate change is treated with the urgency and attention it deserves.” 

But the science does not show a connection between the Marshall Fire and Climate Change. And due to the greed of the media, politicians, and selfish scientists, only scientific integrity is facing a real crisis. 

 Finally, it is worth noting that some scientists are acutely aware of the increasing fire danger presented by the build-up of dead vegetation. To remove that hazard prescribed burns are being performed. But sometimes prescribed burns get away and burn down people’s homes. So prescribed burns are carefully planned for times when fires are most easily controlled. So, one must wonder just how unusually dangerous local conditions were if the City of Boulder planned a prescribed burn on Monday, December 13, 2021, just 2 weeks before the Marshall Fire. Had climate change really made conditions so dangerous? 

......

an addendum  1/3/22

Here are Boulder's December temperature and precipitation  trends since 1893 from NOAA. https://psl.noaa.gov/boulder/

No sign of global warming or drying trends

 Jim Steele is Director emeritus of San Francisco State University’s Sierra Nevada Field Campus, authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism, and proud member of the CO2 Coalition.

 Gavin Newsom’s Exceedingly Ignorant Climate Claim

 

Scientific evidence reveals there has been no climate effect regards California’s wildfires! None! The data below proves it beyond all doubt. There is no denying that warmer temperatures can cause drier fuels and promote larger fires. But that fact is being misapplied to all wildfires. About 70% of California’s 2020 burnt areas have been in grasslands and dead grass is so dry by the end of California’s annual summer drought that dead grasses are totally insensitive to any added warmth from climate change. Dead grasses only require a few hours of warm dry conditions to become highly flammable. It’s fire weather not climate change that is critical. Furthermore, the century trends in local temperatures where California’s biggest fires have occurred reveal no connection to climate change. In most cases the local maximum temperatures have been cooler now than during the 1930s. Those cooler temperatures should reduce the fire danger. Newsom is either ignoring or distorting the scientific evidence, is totally stupid, or is a dishonest demagogue.

 

Maximum temperatures are typically used by fire indexes to issue red flag warnings because it is the heat of midday that has the greatest drying effect. Minimum temperatures are often low enough to drop below the dewpoint at which time fuel moisture increases. So averaging minimum and maximum temperatures is inappropriate. In addition, referencing a higher global average temperature is meaningless. Only local maximum temperatures determine the dryness of surface fuels during every fire. As in Park and Abatzoglou 2019, the months of March through October are averaged to determine maximum temperatures during California’s dry season.

 

Here are some relevant facts (from the Western Regional Climate Center).  Trust the scientific evidence

 

 

1) The August 2013 Rim Fire centered around Yosemite National Park, was California’s 5th largest fire.

 

 

2) The November 2018 Camp Fire was California’s deadliest fire destroying the town of Paradise. It was also its 16th largest fire.

 

 

3) The 2018 Mendocino Complex Fire was California’s largest fire (since 1932 excluding 2020) .

 

 

4) In the October 2017 wine country fires, the Tubbs Fire was the 4th deadliest. It only burned 37,000 acres but high winds drove embers into the dwellings of the heavily populated outskirts of Santa Rosa.

 

 

 

 

Governor Newsom ignores the data to disgustingly hijack the tragedy of California’s fires and push his climate change agenda. But he is not alone. There are climate scientists pushing catastrophes by ignoring the local maximum temperature trends. Bad analyses promote bad policies and obscure what needs to be done regards fuel management and creating defensible spaces in fire prone California. Newsom must focus on fuel management and fire suppression. As fire ecologist Thomas Swetnam echoed the experts’ growing consensus against fire suppression wrote, “The paradox of fire management in conifer forests is that, if in the short term we are effective at reducing fire occurrence below a certain level, then sooner or later catastrophically destructive wildfires will occur. Even the most efficient and technologically advanced firefighting efforts can only forestall this inevitable result.”

 

 

Further information about California’s wildfires are

Why Worse Wildfires - part 1

 

Why Worse Wildfires?  Part 2

 

Minimizing California Wildfires

 

Wildfires: Separating Demagoguery from the Science

 

 How Bad Science & Horrific Journalism Misrepresent Wildfires and Climate

 

 

Jim Steele is Director emeritus of San Francisco State’s Sierra Nevada Field Campus and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism

 

Contact: naturalclimatechange@earthlink.net 

 

Why Worse Wildfires part 2

What’s Natural?

Why Worse Wildfires?  Part 2

Fighting the Ranch Fire

Why worse wildfires? The short answer is more humans cause more wildfire ignitions in altered landscapes. Since 1970, California’s population doubled, adding 20 million people. As more human habitat was developed, the increasingly disturbed landscape quickly became covered in easily ignitable invasive grasses (see part 1). To protect human habitat, fires were suppressed and ground fuels increased. Development also expanded a vulnerable electric grid. Furthermore, more people increased the probability of careless fires and more innocent accidents. And sadly, a larger population added more arsonists.

During a typically warm and dry July day, a rancher was innocently driving a stake into the ground to plug a wasp’s nest. Surrounded by dry grass, the hammer’s spark ignited a devastating inferno named the Ranch Fire. Despite sensationalist’s hype, global warming had not made the grass drier. Grass becomes highly combustible in just a few hours of dry weather. And like most of northern California, there has been no warming trend for maximum summertime tempertures. Based on Western Regional Climate Center data, maximum summer temperatures in the Mendocino area had cooled by 3°F since the 1930s. The rapidly spreading Ranch Fire soon merged  with a different fire to form the Mendocino Complex Fire, California’s largest documented fire.

Similarly, a highway accident sparked roadside grasses that kindled northern California’s 7th largest fire, the Carr Fire. 

Summertime cooling trend at Ukia,  Mendocino County, California

Careless fires cannot be considered accidents and offenders should be held accountable. A hunter’s illegal and improperly attended campfire caused the August 2013 Rim Fire, centered around Yosemite National Park. It was California’s 5th largest fire. 

Governments and utility companies should likewise be held accountable for carelessly maintaining our electric grids. An electric spark ignited California’s deadliest fire, the Camp Fire which destroyed the town of Paradise and killed 85 people. As a 2018 research paper estimates, “Since the year 2000 there’ve been a half-million acres burned due to powerline-ignited fires, which is five times more than we saw in the previous 20 years.” 

More disturbing is the number of fires started by arson. According to the U.S. Fire Administration, nationally, as in California, one in every five brush, grass, or forest fires since 2007 were intentionally set. Arsonists have been recently charged for some of California’s 2019 fires. Arson accounted for 55% of Kentucky’s fires and is the leading cause of Florida’s fires. Because arson is so difficult to prove, arson statistics are probably underestimated. So, experts in Australia combine arson and “suspicious” fires to argue half of Australia’s fireswere likely intentionally set. That means each year 31,000 Australian bushfires are intentionally ignited. And as in the American west, Australia’s bush fires have been increasingly fueled by invasive grasses like Buffel grass.

Wildfires caused by natural lightning ignitions, peak during the summer months of July and August, and become virtually non-existent in the autumn and winter. In contrast, human ignitions have created year-long fire seasons. Counter-intuitively, California experiences the most dangerous fire weather during the cooler and wetter seasons.  As seasonally cold air settles in over the high mountain deserts in autumn and winter, episodes of high winds, known as the Santa Ana and Diablo winds, flow downslope. Sinking air warms 5°F for every 1000-foot drop in elevation so these downslope winds can raise lowland temperatures 25°F in just a few hours. That warming causes relative humidity to fall, so these winds rapidly suck moisture out of whatever vegetation it passes over. In combination with faster spreading embers, fires burn 2 to 3 times more area during high wind events.

Human vs Lightning Wildfire Ignitions from Balch 2017

Under natural conditions, seasonally extreme winds never coincided with the season of abundant lightning. But due to human ignitions there has been an increased probability of more ignitions occurring during strong cool-weather winds. California’s 2nd biggest fire, the Thomas fire, was ignited in December by a downed power line during high winds. The third largest fire, the Cedar Fire was ignited in October by a lost hunter who carelessly lit a signal fire. California’s deadliest fire, the Camp Fire, was ignited by a powerline and fiercely spread due to a November high wind event.  

Climate change does not ignite fires. Climate change does not affect how quickly dead grasses and bushes can dry. Climate change may affect the winds, but any warming, natural or human, would reduce those extreme winds. Regards California’s worst fires, a US Geological Survey’s wildfire expert states, “Some will argue that it’s climate change, but there is no evidence that it is. It’s the fact that somebody ignites a fire during an extreme [wind] event.”

Jim Steele is Director emeritus of San Francisco State’s Sierra Nevada Field Campus and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism

Contact: naturalclimatechange@earthlink.net 

Why Worse Wildfires? Part 1

What’s Natural?

published in the Pacifica Tribune, November 20, 2019

Why Worse Wildfires? Part 1

SAGE GROUSE LEKKING

There are several theories trying to explain the recent uptick in wildfires throughout the western USA. Some scientists blame increased human ignitions. Others suggest accumulating surface fuels due to a century of fire suppression. Others argue landscape changes and invasive grasses have amplified the amount of easily ignited vegetation, while still others blame climate change. What’s the Sage Grouse connection? Like human communities, the Sage Grouse’s habitat is being threatened by fast spreading wildfires, and that increase in bigger wildfires in sagebrush country is due to invading annual grasses, like cheatgrass.

Historically hot dry sagebrush habitat rarely burned (just once every 60-100 years) because slow growing, patchy sagebrush only provides scant surface fuels incapable of supporting large and frequent fires. But the invasion of introduced annual grasses, like cheatgrass, has changed all that. As one wildlife researcher lamented, “The color of Nevada has changed from a sagebrush silver gray to a cheatgrass tawny brown since the 1990s”.  Likewise, in the 1800s California’s hills were covered with perennial grasses that stayed green during the summer. Now California’s hills are golden brown as highly flammable annual grasses have taken over.

Cheat grass-dominated sagebrush habitat now burns every 3-5 years, up to 20 times more frequently than historic natural conditions. Extensive research on the effects of cheat grass found habitats with high cheat grass abundance are “twice as likely to burn as those with low abundance, and four times more likely to burn multiple times between 2000-2015.” What makes cheatgrass such a problem?

Invading annual grasses germinate earlier in the season and deprive the later-germinating native grasses of needed moisture. These foreign grasses die after setting seed, leaving highly flammable fuels that can burn much earlier in the year and thus extend the fire season. Eleven of the USA’s 50 biggest fires in last 20 years have been in Great Basin sagebrush habitats, where invasive cheatgrass is spreading. Nevada’s largest fire was the 2018 Martin Fire. Rapidly spreading through the cheat grass, it burned 439,000 acres, a burned area rivaling California’s largest fires in recorded history. 

Cheatgrass in Juniper Woodland

The 2012 Rush Fire was California’s 4^th largest fire since 1932, burning 272,000 acres of sagebrush habitat in northeastern California. It then continued to spread burning an additional 43,000 acres in Nevada. The 2018 Carr Fire was California’s 7^th largest fire and threatened the town of Redding, California. It started when a towed trailer blew a tire causing its wheel rim to scrape the asphalt. The resulting sparks were enough to ignite roadside grasses. Grassfires then carried the flames into the shrublands and forests, where burning grasses served as kindling to ignite less-flammable trees. Likewise, grasses were critical in spreading northern California’s biggest fires. In southern California, as humans ignite more and more fires, shrublands are being converted to more flammable grasslands.

Wildfire experts classify grasses as 1-hour fine fuels, meaning dead grass becomes highly flammable with just one hour of warm dry conditions. When experts estimate impending fire danger, they calculate the extent of a region’s fine fuels to determine how fast a fire will spread. The amount of small diameter fuels like grasses that can dry out in an hour, as well as twigs and small branches that dry out within 10 to 100 hours of dry weather, determine how fast the winds will spread a fire. It does not matter if it was wet and cool, or hot and dry during previous weeks or years. Just one hour of warm dry fire weather sets the stage for an explosive grass fire. Decades of climate change are totally irrelevant.

Some scientists point out that certain logging practices also spread “invasive grasses”. For that reason, California’s Democrat congressman, Ro Khanna, has been arguing that the U.S. Forest Service policy to clear cut after a wildfire is making California’s forest fires spread faster and burn hotter by increasing the forest floor’s flammable debris. Khanna warns, “Because we don’t have the right science, it is costing us lives, and that is the urgency of getting this right.” 

Bad analyses promote bad remedies and blaming climate change has distracted people from real solutions. The “cheatgrass” problem will continue to cause bigger fast-moving fires no matter how the climate changes. But there are several tactics that could provide better remedies. Holistic grazing that targets annual grasses before they set seed is one tactic. Better management of surface fuels via prescribed burns is another, as well as more careful logging practices. And re-seeding habitat with native perennial grasses or sagebrush could help shift the competitive balance away from cheatgrass. In combination with limiting human ignitions, (see part 2), all those tactics may ensure healthy populations of Sage Grouse living alongside safer human communities.

Jim Steele is Director emeritus of San Francisco State’s Sierra Nevada Field Campus and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism

Contact: naturalclimatechange@earthlink.net 

Deconstructing the Climate Demagoguery of the Wine Country Wildfire Tragedies

Wine Country Fire October 2017

As sure as the winds will blow, climate demagogues hijack every human tragedy to amplify fears of rising CO2 concentrations. Despite the fact that other critical factors were the keys to understanding the devastation of the Wine Country fires, politicians like Hillary Clinton, Al Gore and Governor Jerry Brown were quick to proclaim climate change had made the fires worse than they would have been.

Climate researcher Kevin Trenberth has long tried to undermine the foundations of science by discarding the null hypothesis. Without formal testing whether a tornado, hurricane or wildfire event is within the expectations of natural variability, Trenberth simply asserts every tragedy is made worse by rising CO2. Accordingly, he is interviewed by climate change propagandists after every weather tragedy. In an interview with InsideClimateNews a few months before the Wine Country wildfires Trenberth continued to proselytize his views, “Whatever conditions exists, they're always exacerbated by climate change. There's always that heat variable, the increased risk.”

Indeed heat is always a variable, but usually it has nothing to do with CO2. Sadly, due to his extreme beliefs Trenberth often confuses climate with weather.

Similarly, Daniel Swain who authors a good California Weather Blog, unfortunately strays when he tries to interject CO2-climate change into an otherwise good weather analysis. Writing the fires should also be looked at from “the long-term climate context,” he argued the “record-hottest summer” dried out the vegetation exacerbating the fire conditions. But he too failed to separate natural climate and weather events from his hypothesized contributions from CO2. As will become clear from a more detailed analysis, climate change played no part in the wildfire devastation.

The Ignition Component

Fire danger rating systems analyze 1) an ignition component, 2) a fuel component and 3) a spread component to determine how to allocate fire-fighting resources and when to issue public alerts. Natural fires are caused by lightning, and thus good weather models can forecast the short-term probability of lightning fires. Lightning fires are also more likely during warm and moist seasons enhancing their window of predictability. Unfortunately, Cal Fire reports 95% of California fires are unpredictably ignited by humans.

Climate alarmists like Dr. Trenberth have blithely suggested global warming is increasing the fire season stating, “In the West, they used to talk about a fire season, the fire season used to be 60 days, then 90 days, and now they think it's year-round. There's no pause." Tragically that uncritical belief in a climate-related extended fire season has been parroted by lay person and scientists alike. But the facts show the observed extended fire season is due to human ignitions. Blaming climate change is fake news!

In a 2017 paper researchers reported that across the USA from 1992 to 2012, “human-caused fire season was three times longer than the lightning-caused fire season and added an average of 40,000 wildfires per year across the United States. Human-started wildfires disproportionally occurred where fuel moisture was higher.” Furthermore “Human-started wildfires were dominant (>80% of ignitions) in over 5.1 million km², the vast majority of the United States, whereas lightning-started fires were dominant in only 0.7 million km².”

We can reduce some human caused ignitions. The Wine Country fires were not ignited by lightning but all observations suggest they were started by downed power lines in high winds. A year ago, California legislators introduced a bipartisan bill aimed at reducing wildfire ignitions from powerlines. Although governor Brown hypes the unsubstantiated dangers of climate change, he vetoed the bill which would have promoted real action to prevent well-known human causes of wildfires. Preventing powerline ignition could have prevented the Wine Country tragedy.

The Fuel Component

Fire ecologist will estimate a fire’s potential intensity by calculating the Energy Release Component (ERC), a measure of the potential heat energy per square foot. ERC is a function of the biomass both dead and alive, and the biomass moisture content. As fuels increase and as fuels dry the ERC increases. Live fuels are modeled such that maximum moisture content coincides with the peak growing season, and declines thereafter as the plants go dormant. Moisture content of dead fuels are modeled according to their diameters.

Depending on their diameters, dead fuels will lose moisture as they equilibrate with their dry surroundings at rates that vary from 1 hour to 1000 hours or more. To aid in firefighting management decisions, fuels are categorized into 4 groups as described in Gaining an Understanding of the National Fire Danger Rating System published by the National Wildfire Coordinating Group 

1-Hour Time-lag Fuels “consist of herbaceous plants or round wood less than one-quarter inch in diameter.  Also included is the uppermost layer of litter on the forest floor.” The ERC of these fuels and thus the fire danger, can change throughout the day. Dead grass as well as twigs and small stems of chaparral shrubs are 1-hour fuels, and those fine fuels sustained the rapid spread of the Wine Country fires. Assertions that recent and past summer droughts or decades of climate change had dried the fuels and exacerbated the Wine Country fire danger have absolutely no scientific basis. The approach of the hot, bone-dry Diablo Winds would have extracted all the possible moisture from the dead grasses and chaparral twigs within hours, regardless of past temperatures. Trenberth and Swain simply confused rapid weather changes with climate change.

The critical “long-term context” they never discussed is that a century of fire suppression allowed destructive levels of fuel loads to develop, increasing the biomass component of the ERC estimate. As populations grew, so did the demand to suppress every small fire that could threaten a building. Natural small fires reduce the fuel load, whereas fire suppression allows fast drying fuels to accumulate. Unfortunately, fire suppression only delays the inevitable while stocking more fuel for a much more intense blaze. Local officials and preservationists have long been aware of this problem, and controlled burns to reduce those fuels were being increasingly prescribed. Tragically, it was too little too late.

Prescribed Control Burn

10-Hour Time-lag Fuels are “dead fuels consisting of round wood in the size range of one quarter to one inch in diameter and, very roughly, the layer of litter extending from just below the surface to three-quarters of an inch below the surface.” The fuel moisture of these fuels vary from day to day and modeled moisture content is based on length of day, cloud cover or solar radiation, temperature and relative humidity.

100-Hour Time-lag Fuels are “dead fuels consisting of round wood in the size range of 1 to 3 inches in diameter and, very roughly, the forest floor from three quarters of an inch to four inches below the surface.” Moisture content of these fuels are also a function of length of day (as influenced by latitude and calendar date), maximum and minimum temperature and relative humidity, and precipitation duration in the previous 24 hours. 

Much of the chaparral shrubs produce twigs and stems in size ranges of the 1-hr, 10-hr and 100-hr fuels. These fuels were most likely the source of burning embers that high winds propelled into the devastated residential areas. Again, these dried out fuels are the result of a natural California summer drought and short term weather conditions such as the bone-dry Diablo Winds that arrive every year. 

Figure 2  Moisture content of 3-8 inch diameter fuels from March to December

1000-Hour Time-lag Fuels are “dead fuels consisting of round wood 3 to 8 inches in diameter or the layer of the forest floor more than about four inches below the surface or both”. These larger fuels are more sensitive to drought conditions that existed months earlier, so it could be rightfully argued that a hotter drier July and August made these fuels more flammable in October and exacerbated the fires.

Fire ecologists planning prescribed burns to reduce fuel loads, wait until the 1000-Hr fuels’ moisture content is reduced to 12% or lower. If these larger fuels are dry, it is certain the smaller fuel categories are dry as well, so that all fuels will be highly flammable. As seen in the graph above (Figure 2) 1000-hr fuels reach that critical dryness threshold by July 1^st and remain below that threshold until mid-October when the rains begin to return. Contrary to Trenberth’s blather, California’s fire season has always lasted 90+ days. Undoubtedly the unusually hot and dry 2017 summer would have lowered 1000-hr fuel moisture content even further. Nonetheless those fuels become naturally flammable every summer. Furthermore, these larger fuels were less often burned and thus insignificant factors regards the fires rapid spread. The rapid spread of the fires was due to consumption of the rapidly drying fuels.

Swain is fond of finding a “record setting” metric to bolster his climate change assertions. As such, he noted the “record-hot summer had dried out vegetation to record levels” and linked to a graph tweeted by John Abatzoglou showing October ERC values for the past 30 years were at a record high in 2017 (in part because of delayed rains). However, that “record” was also largely irrelevant. The ERC calculation is heavily biased by the greater biomass of the larger 1000-hr fuels that would indeed get drier as the autumn continued without rain. Still those larger fuels were insignificant contributors to the rapidly spreading fire. As seen below (Figure 3), the grasses have been entirely burnt while the larger shrubs and trees, as well as the woody debris near the base of the trees (in the upper left) have not been consumed. In fact many of the trees are still alive. The potential energy estimated by the “record ERC” was only partially realized. It was the fast-drying dead grass and chaparral shrubs that turned potential ERC into meaningful fiery heat.

Figure 3

The Spread Component

“The spread component is defined as “the theoretical ideal rate of spread expressed in feet-

per-minute.” Wind speed, slope and fine fuel moisture are key inputs in the calculation of the spread component, thus accounting for a high variability from day-to-day." Thus, a combination of dry fuels and high winds typically result in fire-watch and red-flag warnings one day and no warnings days later as the winds subside. Forest rangers are well aware that September and October bring the powerful Diablo Winds to Santa Rosa as well as the Santa Annas to southern California, and with those winds comes the highest fire danger.

Cliff Mass is an atmospheric scientist at the University of Washington and author of the superb Cliff Mass Weather and Climate blogs. An October 16^th post provides an excellent summary of the metorological conditions that created the fierce winds driving the Wine Country fires. In essence, a strong approaching wind flow (the Diablo Winds) coupled with a thermal inversion near the top of the mountains that border the Santa Rosa valley, accelerated winds into a 60 to 90 mile per hour downslope wind event, a phenomenon known as a mountain wave.  Those high winds snapped power line poles and ignited fires. The regional topography also funneled the winds and fire down the valley, taking dead aim at the heart of Santa Rosa. The topography had guided a similar fire in 1964, the Hanley fire, which was started by a carelessly discarded cigarette. Unfortunately without much concern, most of the burnt homes in the Tubbs fire had been built on top of the burnt grounds of that previous Hanley fire, despite public protests.

Were those high winds perhaps exacerbated by climate change? Highly unlikely!

The Diablo Winds affecting Santa Rosa or the Santa Annas of southern California are driven by cooling seasonal temperatures in the high deserts to the east. The inner continent cools faster than the oceans, setting up a pressure gradient driving the winds toward the coast. The winds then heat adiabatically rising 5 degrees Fahrenheit for every 1000 feet of elevation descent. An adiabatic rise in temperature means no added heat from any source and basic physics tells us temperatures can rise adiabatically simply due to compression. Thus an air mass that originated near Flagstaff Arizona at a 6900 foot elevation, could adiabatically warm by 30 degrees as it reaches sea level.

The flow direction of winds are largely driven by unequal seasonal changes in temperatures. During the summer the interior heats faster than the oceans, such that a cooling onshore wind reduces interior temperatures. This pattern reverses in the autumn as the interior lands cool faster than the ocean creating an inland high pressure that drives the Diablo and Santa Anna winds toward the coast.  Despite declining solar insolation, this autmn wind flow causes coastal California to experience some of its hottest days of the year in September and October, commonly referred to as Indian summer. Similarly a pressure system that inhibited the cooling onshore winds around San Francisco, resulted in a record hot summer temperature. By simultaneously opposing cooling sea breezes while bringing warm winds that were adiabatically 5 to 10 degrees warmer, temperatures rise and relative humidity falls. The result is bone-dry hot Diablo winds that suck the moisture from land and vegetation where ever the winds pass.

To restate the forces driving the winds, the Diablo winds are the result of a pressure gradient resulting from an interior that cools faster than the ocean. If CO2 is warming the earth to any significant extent, then we would expect that warming to prevent the inner continent from cooling as quickly as it did decades ago. Thus CO2-global warming would predict a decline in that presure gradient and a weakening of these winds.

Devastated Neighborhoods in Santa Rosa

To summarize, none of the fire components - ignition, fuels, or spread – had been affected by climate change.

Finally, keen observers will notice that entire blocks of houses, and entire neighborhoods were completely burnt to the ground, in contrast to neighborhood trees that often remained relatively unscathed. This suggests that the high winds rapidly carried burning embers from the grassland and chaparral into these developments. While the trees did not trap the embers, the buildings did. I would expect we will soon hear about investigations inquiring into why these residences were not required to erect more fire safe structures, especially when built in a known fire-prone habitat and a high wind corridor. The simple requirement of constructing eaves in such a manner that prevents the trapping of burning embers and fire-proof roofs may have saved many homes.

Indeed there are many lessons that will allow us to prevent such wildfire disasters in the future if we have accurately determined the causes of these fires. Cliff Mass notes that our short-term weather models had accurately predicted the time and place of the fiercest winds. That information could be used to temporarily shut down the electrical grid where power lines are likely to ignite fires. We can bury power lines below ground. We can remove the high fuels loads that accumulated during a century of misguided fire suppression. Insurance companies can demand higher rates unless proven precautions are undertaken. It is those lessons that Gore, Clinton, Brown should be promoting to inform the public. Trenberth and Swain should be informing the people of the natural weather dangers that are inevitable. There is no evidence that climate change, whether natural or anthropogenic, exacerbated the ignition, fuels or spread components of these deadly fires.  And worse their obsessed belief that rising CO2 concentrations worsen every tragedy only distracts our focus from real life-saving solutions.