How We Got Here: The Evolution of Zone 0

From scientific insight to a statewide mandate — and the quiet shift of fire defense onto homeowners.

For decades, California’s wildfire strategy was built on a simple belief: We can stop wildfires if we cut down enough vegetation. ‘Vegetation’ is a fire-industry term that flattens everything — green gardens, shade trees, native plant communities, milkweed, succulents, roses — into an undifferentiated category of “fuel.” Once you call living landscapes ‘fuel or “vegetation”, removing them seems logical, even when science says they are not the cause of home loss.

This belief shaped fire agencies, budgets, and public messaging. It produced millions of acres of “brush” clearance, “fuel breaks”, “vegetation management zones,” and hillside grading projects. But the catastrophic fires of the past 15 years revealed something uncomfortable — plant eradication didn’t stop homes from burning.

Wind-driven fires like the Tubbs, Camp, Woolsey, Marshall, Palisades, and Eaton fires showed that even where living plants were thinned or removed entirely, homes still ignited and burned. Every major post-fire analysis came to the same conclusion: Homes burned because embers landed on vulnerable structures — not because shrubbery or trees carried flames directly to houses.

The Science That Changed Everything

In the early 2000s, U.S. Forest Service fire scientist Dr. Jack Cohen introduced a breakthrough concept called the Home Ignition Zone (HIZ). His research showed:

• Wildfires under extreme wind conditions cannot be controlled.

• Most home destruction begins with wind-driven embers, not flame fronts.

• Live green plants next to the home has little to no impact on whether that home ignites.

• What matters most is the distance between houses, roofs, vents, gutters, fences, siding, decks, debris, and flammable materials such as gasolines, paints and aerosols within the first 0 to 30 feet.

Cohen’s work was later reinforced by field assessments, satellite mapping, and post-fire studies across California and the West. The message was clear: To stop home ignitions, focus on homes — not the wildlands. (Cohen, “A More Effective Approach for Preventing WU Fire Disasters”). This marked a fundamental shift in fire science. But it is not the shift California’s Board of Forestry is adopting.

The Policy Shift That Followed — and the One We Didn’t See Coming

State officials faced a hard truth: If extreme wildfires cannot be stopped, the State cannot promise to protect homes. The policy response quietly changed around 2018–2020: Instead of trying to prevent wildfires, the State shifted to preventing home ignitions — by regulating homeowners themselves. This was the birth of “Zone 0,” a concept rooted loosely in Cohen’s idea that the first 5 feet around a structure or house are critical.

But what happened next was not scientific evolution — it was political and economic transformation. Cohen’s science emphasized removing flammable household materials — junk, firewood piles, dry debris — cleaning roofs and gutters, fixing vents, upgrading siding and eaves, and pruning out dead plant matter.
He never recommended removing healthy, living plants or trees.

California took this expert advise and rewrote it into a mandatory 5-foot plant-free zone requiring homeowners to strip away gardens, shrubs, and even trees around every structure in the Very High Fire Hazard Severity Zone, despite this not being what research said. In fact, Cohen’s work clearly states, “clearing vegetation is not necessary” and “shrub and tree canopies do not spread high-intensity fire through communities.” (Cohen, 2018 & 2020 examinations).

So why did California reinterpret the science another way?

The Quiet Engine Behind Zone 0: Privatizing Fire Defense

Three forces converged:

1. Insurance industry pressure. Insurers have long used private risk models — not the State’s fire hazard map — to decide who to insure. Zone 0 gives insurers a new compliance metric, a new reason to non-renew policies, a new basis for claim denial, and a new private market for “risk mitigation services”.

2. State agencies acknowledging their own limits. Behind closed doors, agencies admitted the uncomfortable truth — they cannot control extreme fires under wind-driving conditions, they cannot evacuate entire communities fast enough, and they cannot promise fire suppression will save homes. Rather than say that to the public, the State has shifted responsibility and cost for fire protection from government to individual homeowners.

3. The rise of a wildfire defense marketplace. Private wildfire services, ember-defense companies, proprietary risk scores, and “home hardening packages” have exploded almost overnight. Zone 0 creates a guaranteed customer base, mandatory compliance work, repeat inspections and a regulatory market around people’s yards

This is the privatization of fire defense — not a wildfire safety program.

The Budget Reality Behind Zone 0

The State has framed Zone 0 as a “science-based” wildfire solution. But the financial data tells a different story.

CalFire’s Emergency Fund fire suppression expenditures — the money the State spends trying to put out fires once they’ve already escaped initial attack — have exploded over the past decade. A public graph from CalFire shows suppression costs rising from around $100–$200 million in the early 2000s to nearly $1 billion annually by 2018–2020. The projections remain equally high in the years that follow.

This is the part of the wildfire story that rarely gets discussed:

Suppression costs skyrocketed because the State cannot control wind-driven megafires.

Zone 0 emerged in the same period when:

• suppression failures became impossible to hide

• agencies quietly acknowledged their limits

• the State shifted risk and responsibility onto homeowners

Rather than publicly admit that extreme fires cannot be controlled, California changed the narrative: the problem must be the homeowner’s yard.

When Courts Confirm the Problem: CalFire Ordered to Correct Its Vegetation Removal Program

Adding to the evidence that California’s vegetation-removal strategy is failing, a major court ruling this year found that CalFire’s statewide Vegetation Treatment Program — the same philosophy underpinning Zone 0 — may actually increase wildfire risk.

In California Chaparral Institute & Endangered Habitats League v. Board of Forestry (the agency writing the Zone 0 mandate), the California Court of Appeal ruled that CalFire failed to adequately assess how clearing native chaparral and sage scrub leads to type conversion — the replacement of slow-burning native ecosystems with fast-growing, highly flammable non-native invasive grasses.

The court warned that CalFire’s approach could worsen fire danger, not reduce it. The San Diego County Superior Court subsequently ordered CalFire to correct the program, concluding:

“The initiative risks worsening blazes by removing native plants.”

This ruling directly undermines the core assumption driving both CalFire’s wildland vegetation strategy and Zone 0: the belief that removing living green plants increases safety. The courts have now acknowledged what ecologists have said for years — California’s plant-clearing programs can destabilize ecosystems, destroy biodiversity, and create more flammable landscapes.

In other words, the State is doubling down on a strategy that the courts say may make fires worse, while demanding homeowners pay the price for its failure. If CalFire cannot legally justify removing native plant communities in the wildlands, how can the Board of Forestry justify forcing homeowners to remove native plants in their yards?

Where Are the Environmental Groups?

One of the most revealing parts of the Zone 0 story is who has opposed it — and who hasn’t. For a statewide mandate that removes living plants from millions of yards, accelerates canopy loss, destroys habitat, and worsens heat, you might expect California’s major environmental organizations to be leading the pushback.

Instead, they are missing.

This silence is especially striking because AB 3074 — the law that gave us Zone 0 — explicitly required the State Fire Marshal to consult with “the environmental community” alongside the building industry, insurers, and local government. The statute assumed these organizations would act as a safeguard for ecological integrity.

But when the time came, that safeguard never materialized.

Groups such as the Center for Biological Diversity and The Nature Conservancy declined to engage when approached by concerned residents. Sierra Club has supported Zone 0. Several respected local nonprofits — including the California Native Plant Society, Theodore Payne Foundation, TreePeople, and the Resource Conservation District of the Santa of the Santa Monica Mountains — appear on State-backed Zone 0 outreach materials after accepting wildfire-education grant funds.

To their credit, some of these organizations have since shifted to more nuanced, ecologically grounded positions. But the dynamic itself is telling: when environmental nonprofits rely on State grants, they can be placed in the uncomfortable position of endorsing a policy that destroys the very native plants, habitat, and shade they claim to protect.

It is the same dynamic exposed in the documentary Planet of the Humans: a movement so entwined with government funding and “public-private partnerships” that it becomes reluctant to challenge harmful policies.

And so, in the Zone 0 fight, the organizations with “ecology,” “native plants,” shade, and “land stewardship” in their mission statements stayed silent — leaving homeowner groups across Los Angeles to defend biodiversity, shade, and ecological common sense on their own.

Zone 0 hasn’t just exposed a failure of fire policy. It has exposed a failure of environmental leadership.

What Zone 0 Really represents

Zone 0 marks a profound shift in California wildfire policy from public agency responsibility for fire suppression and fire fighting to private homeowner responsibility for home survival; from managing statewide risk to scoring and policing individual parcels; from ecological stewardship to plant eradication around homes; from shared civic obligation to homeowners bearing all the costs, liability, and consequences.

This shift was not publicly debated. It has been happening through emergency regulations, agency memos, and administrative rulemaking — all framed as “science-based,” even though the science does not support plant elimination.

How Zone 0 Quietly Serves Housing Interests

There is another dimension to Zone 0 that rarely gets discussed — it helps clear the path for development in fire-prone areas.

For years, California’s housing advocates and certain state agencies have argued that wildfire regulations — especially local tree protections, ecological standards, and discretionary approvals — “stand in the way” of building more housing. By redefining plants as a hazard and creating a universal mandate to remove it within the first 5 feet of every structure, the State effectively reframes ecological landscapes as code violations, not community assets.

Under this policy: green canopy and habitat becomes a liability rather than something worth preserving. Hillside parcels that were long considered inappropriate or too risky for development can now be reframed as “buildable,” as long as they are stripped of entire plant communities. Cities face pressure to permit new housing even in historically unsafe locations, because the State can claim Zone 0 mitigates the risk to “less than significant”. Developers benefit from a simplified regulatory landscape where natural environmental concerns are treated as secondary to fire compliance.

In practice, Zone 0 does more than shift fire responsibility onto homeowners — it also accelerates a political agenda that treats hillsides, canyons, and wildland-adjacent neighborhoods as new frontiers for development. Ecology becomes expendable. Living green yards become the enemy. And long-standing environmental protections are weakened in the name of “fire safety” and housing “opportunity sites”.

This convergence of wildfire policy and housing policy is not accidental. It is structural. And it explains why Zone 0 is being pushed so aggressively despite the scientific evidence that plant removal does not stop homes from burning.

The Consequences: Environmental, Social, and Economic

Zone 0 may sound simple — “remove plants near homes” — but its impacts are profound in the urban environment such as loss of native plant communities and leafy green canopy and privacy, decline of pollinators and songbirds, increased erosion and slope instability, higher neighborhood temperatures.

While a growing private industry profits from mandated work, renters and low or moderate income homeowners bear the costs, which can include fines, property liens, and non-renewals. Compliance becomes yet another obstacle to insurance and housing affordability.

What Should Be Adopted Instead

If California followed the actual science, Zone 0 would look like ember-resistant vents, class A roofs. sealed eaves, noncombustible fencing attached to homes, fire-resistant window glazing, gutter guards, removal of junk, debris and firewood piles from next to the home, plus well managed living green shade yards.

This is what the experts — including Cohen — recommend. Not bare-earth buffers. Not moonscaped yards.
Not punitive inspections. Not the criminalization of defensible space.

Where We Go From Here

The path forward is already clear. Harden homes. Use targeted, not destructive, horticulturally sound landscape practices. Support communities, not punish homeowners. Adopt policies grounded in real science — not industry pressure, and stop adding more buildings to the WUI. California’s wildfire problem is real. But the solution cannot be to criminalize defensible space or turn millions of private yards into sterile enforcement zones while letting insurers and the State walk away from responsibility.

Zone 0 didn’t evolve from science. It evolved from politics, economics, and the quiet privatization of fire defense.

And homeowners deserve to know the truth.