Chaparral Wisdom

The Stupidity of Zone Zero
and Other Feckless Fire Commandments in California

One would think that after increasing losses of life and property from wildfire every decade, California would reconsider its forest-centric, clearance-of-habitat approach to fire risk reduction. Instead, the state is doubling down on removing even more greenery to the tune of millions of acres.

The latest symptom of this plants-are-the-enemy paradigm is Governor Newsom’s executive order to eliminate your right to enjoy azaleas under your bay window. In fact, the government is headed toward requiring not much more than bare dirt, concrete, or jumbles of rock within the first five feet of our homes, the so-called Zone Zero.

Sorry mom, dad, by government decree, the azalea that was part of our family garden for decades would be cut down. And if it wasn’t, the government would hire out to forcibly have it done and charge you for the courtesy. No matter that hydrated trees and shrubs can aid in protecting homes from flying embers, the primary cause of home ignition during wind-driven wildfires.

Mom and dad, proud of the legacy azaleas they had nurtured for decades, next our the family home.
Photo: March, 1994.

What’s the cause of yet another government intrusion into our lives? Paradigm blindness, based on assumptions that are irrelevant to most of us.

The state bureaucracy thinks we all live in semi-rural, forest settings with ranch homes on one acre lots (so we can clear 100 feet of “defensible” space), with trees that need to be “limbed up,” and where “ladder fuels” need be cleared. And, of course, there is a fire station down the street that has the resources necessary to protect us from any fire threat.

Except we don’t. Wildlands are often miles away, and walls of flames coming from a burning forest are not the problem during the wind-driven firestorms that actually inflict the most damage. And, as many have learned during past wildfires in California, a fire engine will likely never show up when the ember rain occurs. We’re on our own.

It’s an old story. Devotees of out-dated paradigms are incapable of seeing contradictions and data that do not conform to their paradigm’s rules. As a consequence, cognitive dissonance blinds government officials, and much of the public, from seeing the obvious. Most of us live in suburban communities. Our neighbors are tens of feet away. Our gardens are filled with hydrated shrubs and trees, not dry, ponderosa pines. And when it matters most, there likely won’t be any firefighters available to use the “defensible” space to defend our homes.

“The moment one has offered an original explanation for a phenomenon which seems satisfactory, that moment affection for his intellectual child springs into existence… There is an unconscious selection and magnifying of the phenomena that fall into harmony with the theory and support it, and an unconscious neglect of those that fail of coincidence.”
– Thomas C. Chamberlin. 1890

It’s Embers, not Flames

The dry “fuels” we need to worry about are our homes. And the image we have of walls of flame taking out neighborhoods? It’s an image that fits with our personal experiences, from campfires to the catastrophizing news reports we see, but the image is wrong. Homes ignite primarily by swarms of embers (Moritz et al. 2014), a phenomenon that is generally foreign to us.

It’s embers that caused the devastation to neighborhoods like Coffey Park in Santa Rosa, the Kilcrease Circle trailer park in Paradise, and the communities of Altadena and Pacific Palisades in Los Angeles County, not flaming gardens. Embers can travel a mile or more ahead of the actual fire, taking advantage of the weakest link, such as cleared, defensible space, open space that can create a bowling alley for embers to target homes like so many bowling pins.

The 2007 Witch Creek Fire, where more than 1,200 homes were burned, provides a typical example.

“Wind-blown embers, which can travel one mile or more, were the biggest threat to homes in the [2007] Witch Creek Wildfire [San Diego County, CA]. There were few, if any, reports of homes burned as a result of direct contact with flames” from wildland fuels.
Institute for Business and Home Safety. 2008.

Catastrophe-by-embers is an easily observed phenomenon that has been repeated in every wind-driven wildfire impacting communities. Countless examples can be found by examining post-fire scenes of burned homes surrounded by unburned green trees and shrubs. It is an observation we have endeavored to share with policy makers since the 2003 Cedar Fire in San Diego. It is an issue US Forest Service fire scientist Dr. Jack Cohen quantified and tried to communicate many years before to a frustratingly dismissive agency. Unfortunately, the predominant plants-are-the-enemy paradigm stands strong, causing cognitive blindness from the governor’s office, to the fire bureaucracy, to individual home owners.

Aerial photo shows the devastated Kilcrease Circle trailer park community after the 2018 Camp Fire in Paradise, CA. Notice the surrounding, green, unburned conifer forest. Satellite image courtesy of DigitalGlobe, a Maxar company, November 2018.

Embers from a burning stand of chaparral (charred sticks in foreground), jumped over an ice plant-covered clearance zone, then a dense patch of old-growth chaparral, and finally over to a home, igniting it. Also note tall, unburned Eucalyptus trees in the background, erroneously labeled by some as “gasoline trees.”
Photo from the 2007 Witch Creek Fire, Escondido, CA.

Aerial photo shows how radiant heat from burning homes ignited by embers, ended up igniting the nearby forest, not the other way around. From the 2000 Cerro Grande Fire, NM, a controlled burn that got out of control.
Photo courtesy of Craig Allen.

Confirmation Bias

In an embarrassing example of confirmation bias, Cal Fire offered a demonstration during a November 3, 2025 Zone Zero workshop to the California Board of Forestry. The demo was designed to support the government claim that garden plants within five feet of a home need to be eliminated because such plants catch fire and are responsible for igniting homes through flame or radiant heat during wildfires.

In the demo, a large stack of wooden pallets was ignited, then nine industrial fans blew the flames directly toward a row of shrubs ten feet way (some hydrated, some dried out). Not surprisingly, the shrubs ignited within minutes, hydrated or not.

Demonstration to show that shrubs will ignite if exposed to heat from flaming wooden pallets ten feet away when flames are blown toward them by industrial fans. From the 11/3/2025 Board of Forestry Workshop on Zone Zero.

The obvious problem with the demo is that it was set up to “prove” a prior assumption, not to discover the actual cause of home ignition during wildfires. This is not science, but cherry picking.

The point of this demo appears to have been in response to testimony given during the many contentious Board of Forestry Zone Zero hearings challenging the plants-are-the-enemy paradigm by citizens who experienced the 2025 Los Angeles fires first hand, witnessing what happened. Many suggested that hydrated shrubs and trees near homes didn’t seem to pose, but actually appeared to reduce, fire risks by creating a barrier to embers. The science supports their testimony.

Bare Zones Increase Ember Production and Loft

When fires interact with patchy vegetation (i.e., fuel breaks, defensible space, Zone Zero), ember production increases (Koo et al. 2010). It is a matter of fluid dynamics – in this case, the flow of hot air. When fire reaches a bare zone, air flows are uninterrupted. This decreases drag, pulling stagnant or slower moving particles (embers) along the way, lofting them into faster moving gusts. However, when trees or other vegetation are present, the flow of wind is disturbed, decreasing the lofting of embers and the wind’s speed. In addition, hydrated vegetation resists ember ignition. Therefore, the removal of hydrated vegetation can lead to increased ember generation and transport, increasing the risk of home ignition.

“Green, well-maintained plants can slow the spread of a fire by serving as heat sinks, absorbing energy and even blocking embers. This apparent protective role has been observed in both Australia and California studies of home losses.”
– Moritz and Carmignani 2025

Ironically, even though state bureaucracies have begun to acknowledge that embers (not flames from plants) are the primary source of ignition of homes when it matters most, they still can’t give up on their forest-centric, plants-are-the-enemy paradigm. Homeowners are saturated with the need for 100 feet of “defensible space,” “limbing up” trees, and removing “ladder fuels,” despite the fact that such advice is not particularly relevant to typical suburban communities. Such is the power of paradigms, which led physicist Max Planck to write, “A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it” (In Gaynor 1949: Max Planck. Scientific Autobiography and Other Papers, pp. 33-34).

Urban Conflagrations and Machine Guns

Once homes start igniting from embers, the burning homes then ignite everything around them, including nearby homes, by massive amounts of radiant heat from flames and additional embers, creating the urban firestorms that are impossible to extinguish. The firestorms stop when either the weather changes, house fuel runs out, or the Pacific Ocean is encountered.

Under firestorm conditions, can garden plants ignite, then cause homes to do the same? Of course. Is it a significant factor in urban conflagrations? The phenomenon has not been properly quantified, but we do know that hydrated green landscape plants and trees are not the culprits the defensible space and the plants–are-the-enemy paradigms claim. We have enough evidence to indicate properly maintained garden trees and shrubs reduce fire risk, and not in the trees-as-lollipops/bare ground preferences shown in defensible space diagrams. We also know that surrounding vegetation is usually ignited by burning homes, not the other way around.

California’s continued focus on requiring the elimination of plants around homes and the clearance of millions of acres of habitat in response to wildfires is similar to what generals did in World War I. The generals kept sending men charging into the opposing line, seeing them ripped to shreds time and time again. Like the generals, California’s fire bureaucracy can’t see the machine guns.

“Dead battles, like dead generals, hold the military mind in their dead grip and Germans, no less than other peoples, prepare for the last war.”
– Barbara W. Tuchman: The Guns of August (1962)

When Democracy Works

Fortunately, the power of democracy has forced the Board of Forestry to decide that it could not meet the governor’s December 31, 2025, deadline for Zone Zero regulations. It suspended further hearings until this coming March, 2026.

The thousands of citizens who participated in the hearings and submitted thousands of comment letters made it clear to the government that they would not tolerate edicts from above that would compromise their standard of living as well as making their homes less fire safe.

Had this been 1994, I know my mom and dad would have attended and been in the first row of those hearings – all of them.

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Other Pernicious Fire Paradigms

The Fire Suppression Fallacy

How did the observation that fire suppression has caused some dry ponderosa pine forests in the Southwest to miss several natural fire cycles metastasize into a pernicious stereotype that has convinced huge numbers of people that Nature is sick, clogged with unhealthy vegetation, and needs to be cleared immediately? The propaganda has been incredibly successful, convincing politicians to allocate billions of dollars to “fix” Nature with grinding machines, chainsaws, and herbicide.

The fire suppression fallacy is the foundation underlying most habitat clearance projects. Please become familiar with the fallacy in our paper on the subject here: The Beginnings of the Fire Suppression Fallacy.

Exploiting Native American Fire Use

Chaparral and sage scrub evolved in California over ten million years as the climate warmed and dried. About 25,000 years ago human arrived, and with them, their fire. For thousands of years, as these new inhabitants created localized relationships with the landscape, the chaparral’s historical fire return interval averaged between 30 to 150 years or more, with large fires occurring 2-3 times per century when drought and extreme weather conditions occurred. Once villages were established and the population reached a dynamic range in line with the environment’s carrying capacity, fire use was focused locally in areas where plant communities were regularly modified, not throughout the wild landscape. Along the coastal plain, native shrublands were type converted to preferred herbaceous plant communities by repeated fires.

When Europeans arrived, they brought with them annual grasses that took advantage of the type converted landscapes, spreading widely. These grassy areas have continued to expand due to high fire return frequencies and soil disturbance, creating the non-native, weedy (and flammable) grasslands that dominate much of California today.

There is a pervasive myth, however, that Indigenous Peoples carefully used fire, not to modify the landscape to suit their needs, but to ecologically manage habitat across the entire state. Fire and resource agencies, environmental groups like the Nature Conservancy, and research institutions like the College of Natural Resources at the University of California, Berkeley, have promoted this myth to justify the clearance of habitat through prescribed fire, logging and other means. Despite significant contrary scientific evidence, these entities claim natural, dense habitat across the West is an anomaly, existing only because European settlers and the government stopped Indigenous Peoples from using fire (see the fire suppression fallacy above). In other words, nature cannot survive on its own and requires human intervention.

Governor Newsom included the need for “cultural burning” in a recent executive order exempting many habitat clearance projects from environmental oversight. The Association for Fire Ecology even claims that Indigenous beliefs and stories about fire use are science.

Science is one of the few tools we have to eliminate bias, self-interest, and memory embellishment, behaviors all humans exhibit. No matter what an idea is, or where it came from, it must be subject to the same objective analysis as any other idea. It must be able to be challenged. Unfortunately, the Indigenous ecological fire myth has been subsumed by identity politics, becoming unquestionable dogma. The professional and personal costs of challenging this dogma can be significant.

Unquestionable dogma is not science.

When the ecological fire dogma is challenged, it quickly becomes apparent that it fails to account for a large number of variables that did not exist centuries ago: the invasion of flammable, non-native weeds, climate change, increased ignition sources, and an increasing human population. Failure to acknowledge that frequent fire in native shrublands has destroyed, and continues to destroy, habitat and biodiversity is another blind spot, a blind spot that has had serious consequences as it inspires policy and land management practices (i.e., when prescribed burns are proposed in shrublands, a practice that only adds more fire to landscapes that already suffer from too much).

Grass Kills

The clearance of native shrubland and forest habitat ultimately leads to a more flammable landscape through the spread of non-native weeds and grasses. Recent wind-driven wildfires that were fueled by grasses demonstrate this with depressing clarity.

1. 2023 Lahaina Fire, Maui – 102 fatalities, 2,207 structures burned, 17,000 acres
2. 2021 Marshal Fire, Colorado – 2 fatalities, 1,091 structures burned, 6,026 acres
3. 2006 Texas Panhandle – 12 fatalities, 723 structures burned, 1 million acres

Every wildland firefighter is trained to know that the most dangerous fuel type is grass; the presence of grass is one of the common denominators in wildland firefighter fatalities.

So, unless we intend to pave over all undeveloped land, flammable, annual, non-native grasses and weeds will grow readily and dry out every year in previously cleared landscapes, fueling the next catastrophic wildfire. A recent California Appellate Court ruling informed the state that it needs to account for this increased flammability in its Vegetation Treatment Program. Ironically, despite all the rhetoric about preserving biodiversity from Governor Newsom’s office and the California Legislature, the loss of habitat and wildlife caused by the state’s planned habitat clearance projects is never acknowledged.

Exterior Sprinklers

Interior fire sprinklers were a wonderful invention that protected factories from fires within. They were later installed in concentrated communities like high rises and have been credited to saving lives. In 2011, interior fire sprinklers were required in new homes and duplexes in California as a life saving measure.

However, the fundamental handicap interior fire sprinklers have is that they are focused on extinguishing fire that starts inside a structure. That does not help in California wildfires as the fire comes from the outside. This fact has yet to sink into the mindset of policy makers or the public as the urban interior sprinkler paradigm is preventing clear thinking. The concept of exterior sprinklers to hydrate the outside of a home and the surrounding environment remains a foreign concept and often elicits intense opposition.

Fortunately, private individuals and companies are utilizing the exterior sprinkler concept, learning from their successes in Canada and Australia. Exterior sprinklers are not fail safe, but they do successfully exploit a basic law of physics – wet homes and plants do not burn. More about exterior sprinklers in our online journal here: Exterior Fire Sprinklers Save 188 Properties – Wet Homes Don’t Burn.

Solutions

For solutions to the wildfire threat, please see our webpage, Protecting Your Home.