California is pilfering its forest-carbon treasure chest and compounding wildfire risk

Evan Mills, Ph.D.
10 min readSep 18, 2021

Evan Mills, Ph.D. & John P. O’Brien, Ph.D.

Forests are carbon storehouses … until they’re not.

While on the one hand California is a leader in climate change solutions, state policymakers are also undermining their own bold commitments by logging publicly-owned forests and thus pilfering a massive carbon treasure chest.

Contrary to popular perception, these practices also amplify wildfire risk. Sadly, Cal Fire’s rhetoric and management of state forests — and their rubber-stamp approvals of virtually every private logging plan — runs directly counter to the latest science and the state’s own efforts to reach its emissions-reduction targets, including initiatives such as Governor Newsom’s “30x30” plan.

We highlight the situation in the state’s own 75-square-mile Jackson State Demonstration Forest (“Jackson”) — a glorious population of redwoods now slated for massive logging — as an example of these counterproductive practices. We advocate for preservation of the remaining public forest lands and reform of logging practices on private lands.

We have penned a commentary for the San Francisco Examiner, making the latest scientific insights accessible to general audiences. You’ll find our piece online here and in their Sunday, September 19th print edition. Below, we provide further references and visuals about the underattended logging-carbon-wildfire nexus.


Evan Mills is a California-based energy and climate policy analyst who participated as lead author in the work of the Nobel-Prize-winning Intergovernmental Panel on Climate Change. He is an Affiliate and retired Senior Scientist at the US Department of Energy’s Lawrence Berkeley National Laboratory and Research Affiliate at UC Berkeley’s Energy and Resources Group.

John P. O’Brien is a postdoctoral climate science research fellow at the National Center for Atmospheric Research, Climate and Global Dynamics Division and a research affiliate at the Lawrence Berkeley National Laboratory, Climate and Ecosystem Sciences Division.


  • Logging does not effectively thwart wildfires, and indeed can make them worse. Following are maps of the perimeters of the Caldor and Dixie Fires (2021), with illustrations of the heavy pre-fire logging that clearly did not curb the fires’ trajectories.
The 160,000-acre Caldor fire (as of August 28, 2021) burned rapidly through many square miles of recently logged and “treated” forests. This is just the latest evidence that logging’s fire-safety benefits are poor at best.
  • Controlled burns and light-touch fuel reduction do thwart wildfires. In September 2021, writers and graphic artists at the San Francisco Chronicle did a marvelous job illustrating how prescriptive fire and ecologically sensitive fuel-reduction “treatments” interrupted the Calder Fire of its power as it approached Tahoe City. The Caples Ecological Restoration Project in particular, will ultimately conduct controlled burns across 8,850 acres of forestland. As shown in the diagram below — unlike the case for the many surrounding industrial logging tracts — areas treated thus far deflected the fire. While these strategies are essential, the article ignored the root problem of how commercial logging compounds fire intensity and spread. Efforts to improve fire resilience without also curbing risk-enhancing logging are just a “one-handed clap.” That said, some such efforts (such as the Sierra Nevada Conservancy and USFS project in the same area) are heavily focused on biofuel production (which typically results in net carbon emissions) large trees for revenue irrespective of impacts on forest health.
Proactive controlled burns and light fuel reduction under the Caples Ecological Restoration Project (yellow) resisted the Caldor Fire in 2021. Source: Jung and Friedrich, Yoohyun Jung and Paula Friedrich, San Francisco Chronicle, 2021.
  • In a rare moment of candor, CalFire admits that logging refuse makes wildfires more intense.

KMUD: Do firefighters have to be strategic fighting, you know, incidents on logging lands as there’s a lot of slash files and stuff of that nature?

CAL FIRE: It it requires a change in tactics. The fire is usually hotter, has a little bit greater intensity just because of all the fuel that’s on the ground, so it takes usually heavy equipment like our our dozers to get in There. Iit requires much more water, so additional water tenders were ordered, additional aircraft were ordered. In order for retardant and helicopter bucket drops to get through the canopy and down into the heavier fuels that were on the ground as well.

  • Some fuel breaks do more harm than good, and divert funds from more effective fire risk reduction strategies. The creation of fuel-breaks (no doubt sometimes doubling as an opportunity to clear-cut significant numbers of trees for lumber) has been found to provide less protection that might be assumed. Blowing “blizzards of embers” (a phenomena enhanced by logging) can travel miles, easily bypassing relatively narrow fuel breaks. This LA Times piece dramatically illustrates how extensive fuel-break networks were breached by the infamous Camp Fire (which destroyed the town of Paradise in northern California in 2020) and the Thomas Fire (which raged in 2018 in southern California). Other infamous California fires — (Tubbs, Cedar, Woolsey, etc. — were also unimpeded by fuel breaks. While fuel breaks are useful against slower-moving ground fires, it’s fair to ask whether the $32 million being spent — by none other than Cal Fire — might be more effectively deployed toward other strategies like hardening homes. Preventing property loss is, after all, the prime goal of fire suppression. The piece cites one expert saying that “fuel is one of the least important factors when it comes to protecting the home.” A Los Angeles fire official agrees, and the city has virtually ceased its long-standing fuel-break programs given sparse evidence of their efficacy and extensive negative environmental consequences. Yet, in its inimitable wisdom, the state has cut a $1 billion incentive program to harden homes, while planning to spend $1 billion on further “fuel-reduction” projects.
Fuel breaks nearly surrounded the doomed town of Paradise, CA prior to the Camp Fire of 2018. Like many other mega fires, those breaks did not save the town. Source: Los Angeles Times
  • Buildings are the fuel of concern, not trees. If there is any question that the buildings are the key fuel of concern, several of the photos of the aftermath of the Dixie Fire published in this September 2021 by the LA Times make it painfully clear. The following one, in particular, shows untouched forests very completely burned close homes and businesses in Greenville, CA. Virtually the entire town was destroyed in the fire.
Buildings are the key fuel of concern. Homes and businesses completely incinerated in the Dixie Fire (2021), while thick adjacent forests remained untouched.

Even more damning to the theory that we must cut trees to protect homes, the photo below shows a neighborhood of Paradise after the Camp Fire. Clearly, the homes were the fuel, and, indeed, some trees were singed by the burning homes (not visa-versa).

If one needs more examples, observe the late-2021 Marshall Fire, south of Boulder, Colorado. The blaze, which appears to be nowhere near forests, consumed nearly 600 homes (and a Target shopping complex and a 421-room, 4-storey hotel) in just the first 9 hours (and is still burning strongly at the time of writing).

  • Climate change is forcing redwoods northward, and, in effect, out to sea, drastically reducing their range. Fernandez, et al., delved more deeply into the question of how the range amenable to coastal redwoods will shift under climate change. In the drier and warmer scenarios, about two-thirds of redwoods’ existing range becomes no longer viable by 2050 (after which the trend will only continue). As with many other climate impacts on natural systems, species often have to move. In this case, the sweet spot moves north and offshore. The worst-hit forests are in the central and southern part of their current range, which includes Jackson.

In a July 2021 paper by Coffield et al., scientists at UC Irvine, Stanford, and Lawrence Berkeley National Lab find that forced contraction of redwood forests under future climate change scenarios results in the loss of up to ~100 tonnes of CO2/hectare in parts of northern California. They also find severe northward “migration” pressure on redwoods, as the southern areas become warmer and dryer. Whether these forests can in reality move, how many centuries it would take, and what kinds of constraints they would run into are left for future analysis. The analysis only looks at above-ground carbon, and does not incorporate the effects of reduced fog in coastal areas. Even with these caveats, their results clearly show a grim outlook for redwoods in the vicinity of Jackson Demonstration State Forest. The study also includes an overlay of forests where carbon offsets have been sold or otherwise taken credit for are directly in the line of fire, once again drawing into question the veracity and reliability of these forest-offset schemes.

Coffield et al. (2021),
  • Clearcuts result in particularly fire-vulnerable firescapes. As research teams have found that what the logging industry euphemistically calls “even-aged logging”, meaning clear cuts (and thus all regrown trees being of the same age), results in loss of diversity in tree size and extensive uniform three-dimensional fuel loads over large areas. These fires not surprisingly burn even hotter than normal fires. The photo shows the aftermath one such firescape near the town of Greenville, which was destroyed during the Dixie Fire. Note the uniform size of the trees.
Caldor Fire: August 2021. Example of how smaller, flammable trees are left behind as logging targets the largest,least flammable ones.
  • California is demonstrating bad (not best) practices at Jackson Demonstration State Forest. Managed by the State of California’s Cal Fire agency, Jackson has been repeated logged over the past two decades, and particularly extensive cuts are now underway without regard for the impacts on carbon emissions or whether or not their practices will
Type and vintage of logging operations in Jackson Demonstration State Forest: 1997-present. Source: Mendocino River Alliance. Interactive version —
There are approximately 500 miles of active and abandoned logging roads in the 75-square-mile Jackson State Demonstration Forest, contributing to loss of carbon due to soil erosion, and impeding forest regeneration.
CalFire abandons massive quantities of “slash” in the wake of their logging operations, which in the near term magnifies wildfire risk and in the longer term results in premature return of forest carbon to the atmosphere as the material decays. Source: William Lemos, Ph.D. 2021. “The How Many Salmon Eggs per Board Foot Problem: Roads, Trails, and Resource Protection in Jackson Demonstration State Forest — A Case for Protection.”
Overly dense, dry, and flammable regrowth around the large stump of a well-spaced large tree in Jackson. Photo taken from a road enabling the issue to be easily addressed post-logging, yet years after logging the landscape languishes within the range of a flicked cigarette butt.
Flammable leavings after state-funded logging operations in Jackson Demonstration State Forest. Photos Courtesy of Mendocino Trail Stewards —
Flammable leavings after state-funded logging operations in Jackson Demonstration State Forest. Photos Courtesy of Mendocino Trail Stewards —
Flammable leavings after state-funded logging operations in Jackson Demonstration State Forest. Photos Courtesy of Mendocino Trail Stewards —
  • Abandoned slash often means elevated fire risk. Jackson State Demonstration Forest (JDSF) and CalFire routinely abandon large quantities of slash after logging operations (see photos above). There are a couple of dozen articles in the literature that have looked at the effect of untreated slash on wildfire outcomes. These are nicely summarized (as of 2017) by Evans and Wright. Many studies found that abandoned slash (piles or “lop and spread” strategies) compounded the damage of wildfires. Slash piles can be ignited by embers, and, in turn, generate embers and firebrands that can spread the fire over travel long distance. Slash piles are ideal tinder. They are dry, well aerated, and include fuels of wide-ranging sizes. They are also normally located in open areas, increasing their exposure to wind. The authors appropriately point out that the presence of slash piles does not always exacerbate wildfire activity or severity, e.g., when access is easy, but it is clear that the presence of untreated slash certainly merits concern.
  • The mythology of carbon sequestration in lumber. In 2020, the US Forest Service released a “life-cycle assessment” of energy use and other environmental dimensions of redwood processing at lumber mills. Among other interesting tidbits therein is that more than half of the “roundwood” (tree) arriving at the mill, is waste, and 42% of that waste is burned to produce energy for onsite-uses. While that fuel is typically characterized as “renewable,” the emerging reality is that it is really no different than burning coal when it comes to carbon emissions directly to the atmosphere. This is because regeneration is questionable given current practices, and, at best, it takes many decades to be recaptured by new trees. Given the climate crisis, we have no time for that. The first figure below, based on data from US Forest Service and the Heinz Center reports, finds that only about 32% of the carbon in a live tree makes it into final lumber, which falls to 15% if the emissions from transport process emissions are subtracted. Writing in the journal Carbon Balance and Management, Harris et al. provide a related analysis (second figure below).
Only about a third of the carbon present in a live tree ends up being stored in the final lumber, and half of that is offset by transport and processing.
From Harris et al. (2016).



Evan Mills, Ph.D.

Energy & environment scientist, with 40 years experience developing and advancing climate change solutions.