One Word Matters: Why 'Onsite' Carbon Storage Belongs in AB 2494

Executive summary

AB 2494 (Rogers) updates decades-old management objectives for California's demonstration state forests, including the addition of "durable onsite carbon storage and sequestration" (DOCSS) as a co-equal objective alongside biodiversity, wildfire resilience, recreation, and other public benefits. Opponents within the timber industry already successfully lobbied the legislature to remove the goal of “maximizing” DOCSS and now claim that the more ambiguous "durable carbon storage and sequestration" should be used instead. This substitution would equate carbon unreliably stored in harvested wood products (HWP) to that stored in living trees. This unscientific substitution should be rejected.

Onsite forest carbon storage is proven and substantial: California's forests hold 56% of the state's stored carbon, and restoration forestry—including thinning smaller, more flammable trees—is supportive of, not precluded by, this objective. HWP storage, by contrast, is insignificant and unreliable: it offsets under 1% of global emissions, is not sufficiently long-lived to qualify as “durable”, relies on products unlikely to significantly replace higher-emitting products or provide long-term carbon storage, omits substantial harvest and transport emissions from state accounting, and depends on regrowth rates already declining due to climate change.

Treating HWP as co-equal to onsite storage would rest AB 2494's climate goals on a flawed foundation, at the expense of the bill's other objectives and of other legislation already on the books in California, particularly Governor Newsom’s 30x30 commitment. The evidence supports signing AB 2494 into law and codifying "durable onsite carbon storage and sequestration" as a management objective for California’s demonstration state forests.

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Introduction

Achieving DOCSS in forests is essential to California meeting its conservation, climate resiliency, and climate mitigation goals. For purposes of this paper, DOCSS is defined as the forest land carbon pool—including soil and biomass—as measured in the California Air Resources Board Natural Working Lands (NWL) Carbon Inventory that is resilient to disturbances such as wildfire, disease, and drought over timeframes that are material to avoiding the adverse impacts of climate change. The NWL Carbon Inventory tracks the forest carbon pool separately from carbon stored in harvested wood products (HWP). This distinction matters: DOCSS advances state policy, including conserving 30% of California’s lands and waters by 2030 (30x30), nature-based solutions (NBS), and wildfire resilience. HWP does not significantly contribute to these goals. AB 1757 (C. Garcia & R. Rivas, 2022) already recognized the centrality of NBS to California's climate strategy, and that recognition reflects a broader pattern—the majority of global carbon dioxide removal (CDR) investment now flows toward fortifying natural carbon sinks.  This is not a coincidence. NBS sequester carbon and avoid emissions through restoration and improved management, while also delivering co-benefits for air and water quality, pollution reduction, climate resilience, and the economy: California's working lands alone support nearly 1.5 million jobs and 75,500 businesses, generating $404 billion in sales and $103 billion in worker earnings. NBS also remain far less expensive and more scalable in the near term than technological CDR alternatives. Sustained investment in NBS over the next five years is essential—both to sequester meaningful volumes of atmospheric carbon now and to build resilience against climate extremes. The phrase "durable onsite carbon storage and sequestration" is essential to include in the management definition in AB 2494 to uplift NBS strategy at the moment it matters most.

Source: California Air Resources Board NWL Inventory 2025 Edition, page iv. The graph depicts California’s total carbon stocks by land type in 2022, including domestically produced and retained HWP.

Assemblymember Rogers introduced AB 2494, a bill that updates the management objectives for California's demonstration state forests (DSF)—including a new objective to manage for DOCSS in conjunction with other co-equal objectives. Throughout the legislative process, opponents have sought to strike this objective, arguing that it restricts timber harvest too heavily, that it may conflict with other management objectives such as wildfire resilience or research, and that these conflicts could expose timber harvest plans to litigation. Opponents—predominantly those representing or benefiting from the timber industry—also argued that carbon stored in harvested wood products (HWP) must be recognized as a management objective in its own right, and proposed replacing "durable onsite carbon storage and sequestration" with the broader "durable carbon storage and sequestration." This paper focuses primarily on affirming the DOCSS as a management objective for DSFs and why it does not conflict with sustainable timber harvest and wildfire resilience.

AB 2494 shifts the management objectives for DSFs away from demonstrating commercial logging techniques—with public benefit values like wildlife and recreation treated with secondary consideration—and toward demonstrating restoration forestry, with biodiversity conservation, wildfire resilience, and DOCSS as primary considerations. Make no mistake: DOCSS is included precisely to ensure that carbon stored in forests long-term is prioritized over carbon stored over shorter timeframes in HWP. It is also worth noting that this phrase has been in the bill since its introduction in February; opposition has raised it as a concern extremely late in the legislative process. AB 2494 does not prohibit timber harvesting—it encourages large-scale restoration forestry specifically to achieve biodiversity conservation and wildfire resilience. This matters because, as this paper will discuss further, restoration forestry can improve the carbon sink across California’s DSFs, while amplifying other ecological and economic benefits. 

To effectively shift management priorities toward biodiversity conservation and wildfire resilience, the bill's language must elevate DOCSS as a co-equal primary objective—distinct from, and not interchangeable with, carbon stored in HWP. This distinction is not merely definitional; it reflects real uncertainty about the effectiveness of long-term HWP carbon storage as a climate mitigation measure, particularly when weighed against the well-documented role of healthy, conserved forests in both climate mitigation and climate resilience. Given that uncertainty, prioritizing onsite carbon storage is not just defensible but prudent.

1. DOCSS as an effective climate mitigation and resiliency measure

California's forests, and its DSFs in particular, are among the state's most significant carbon reserves—and how they are managed will determine whether that carbon remains stored or is emitted to the atmosphere. This section makes the case that DOCSS is not only achievable but essential to sound forest management and climate protection. Subsection A establishes the scale of the resource at stake, showing that the forest types found in DSFs, and redwood forests especially, hold some of the greatest carbon stocks—above and below ground—of any ecosystem in the state. Subsection B then addresses a central concern raised by opponents of AB 2494: that prioritizing DOCSS would come at the expense of active management and restoration forestry. The evidence shows the opposite. Properly implemented restoration thinning is not an exception to DOCSS but one of the practices that makes it achievable, provided that management remains attentive to the distinction between sustainable techniques and degradation-prone practices like high-grading of larger trees. Finally, subsection C demonstrates that DOCSS delivers benefits well beyond carbon accounting alone: forests managed for DOCSS are also more resilient to wildfire, drought, and biodiversity loss, providing co-benefits that carbon stored in harvested wood products cannot replicate. Together, these three lines of evidence establish DOCSS as a scientifically grounded, achievable, and multi-benefit objective—one that AB 2494 should continue to require of California's DSFs.

A. DOCSS is an effective climate mitigation measure

DOCSS aids in climate mitigation and provides significant co-benefits as well. Healthy forests store carbon, particularly redwood forests. Globally, between 2001 and 2025, forests represented a carbon sink of -5.1 GtCO₂e/year—more than the entire annual CO2 emissions of the United States. Within the U.S., temperate forest is the largest category of land-based carbon sink, consistently offsetting about 14% of the nation's CO2 emissions. California reflects this same pattern at the state level: according to the California Air Resources Board's Natural and Working Lands Carbon Inventory, forests and shrublands hold 70% of all carbon stored in California, with 53% of that carbon stored below ground in soils across all land types. This inventory underlies Governor Newsom's 30x30 commitment—a goal AB 2494 explicitly incorporates. The carbon stored onsite in these ecosystems far exceeds what is stored in HWP, and these figures do not even account for the biodiversity co-benefits discussed below.  Indeed, emphasizing HWP for carbon storage could create a conflict of interest, motivating increased commercial timber harvesting or practices such as high-grading.

Forest types represented in DSFs—including redwood and Douglas-fir—support the greatest biomass density of any California forest type. Redwood forests have the greatest capacity to store carbon among all forest types, with a mean carbon mass of  150 tons per acre and with mature second-growth coast redwood forests storing up to 339 tons per acre. Old-growth stands store more carbon than forests managed on 50- or 100-year rotations, and this advantage extends below ground: soil organic carbon (SOC) is greater in old-growth redwood forests than in second-growth forests. Contrary to claims that large old trees (of any species) do not support ongoing carbon sequestration, several studies show that large trees continue to sequester carbon throughout their life, and do so more durably than smaller trees thanks in large part to their superior fire resilience. Taken together, this data makes clear that the forest types found in California's DSFs are not incidental to the climate mitigation conversation—they are among the state's most significant carbon reservoirs, and managing them for DOCSS is one of the most effective climate mitigation tools available to the state.

B. Restoration and DOCSS as interrelated mitigation strategies

There is, in general, a positive relationship between forest restoration and DOCSS. Restoration is increasingly critical to recovering lands after disturbances that result in carbon loss, and on the whole, restoration benefits durable carbon sequestration, particularly on lands that have already been disturbed, including by historic timber harvest.  A study commissioned by CAL FIRE showed that DSFs hold only about 10% of their original amount of carbon. According to the Intergovernmental Panel on Climate Change (IPCC), afforestation, reforestation, and forest restoration can increase global carbon sequestration in both vegetation and soils by 0.5–10.1 GtCO2/year—when compared to the 3.5GtCO2/year that vehicles emit per year, this offset underscores just how much is at stake in how California manages its forestland going forward.

This significance is precisely what makes the relationship between restoration and DOCSS worth examining closely, particularly because opponents of AB 2494 have suggested the two are in conflict. They are not: restoration forestry—which relies heavily on thinning—is fully compatible with, not precluded by, DOCSS, and the data on landcover conversion below explains why. During the final eight years of the NWL Carbon Inventory (2014–2022), California's lands shifted from carbon sink to net carbon source, with total stocks declining by roughly 4%. On a per-acre basis, wildfire remains the greatest driver of this loss, with thinning as the third greatest driver; harvest and clearcutting together account for a smaller share of disturbed acres. But acreage alone is a poor proxy for carbon impact: the amount of biomass carbon transformed by a given disturbance depends not just on the type of disturbance, but on whether that disturbance triggers a change in landcover type—that is, whether the land converts to a fundamentally different, non-forest state rather than remaining as forest. This distinction is the key to reconciling DOCSS with active management. Wildfire and clearcutting drove landcover conversion in roughly a third of affected acres (34.3% and 29.9%, respectively), while harvesting, thinning, and biological-chemical treatments drove conversion in less than 10% of affected acres.  Yet when landcover conversion did occur following wildfire or clearcutting, it accounted for the large majority of biomass carbon transformed by those disturbances (74.6% and 67.8%, respectively)—a rate 2 to 4 times higher than what acreage-affected figures alone would suggest.  In other words, it is landcover conversion, not disturbance or timber removal itself, that drives long-term carbon loss. Indeed, some studies go further, showing that thinning can increase carbon sequestration beyond what untreated forests achieve—though this outcome depends on multiple factors, including starting stand condition, rate of regrowth, and the ultimate fate of harvested biomass. Properly implemented restoration thinning, in short, is not an exception to DOCSS—it is one of the practices that makes it achievable.

That conclusion comes with an important caveat, however: not all thinning, and not all harvest, is implemented equally. Thinning and traditional commercial timber harvest can overlap in the sense that both generate revenue, but they are often not the same thing in terms of desired outcome or sustainability. The distinction lies less in the act itself than in how it's applied: unsustainable logging practices can degrade forest stands regardless of label, which is precisely why an updated DSF management framework is needed. High-grading, for example, removes valuable large-diameter trees while leaving behind damaged, diseased, non-commercial, or otherwise less productive trees—reducing carbon stocks and impairing the forest's subsequent recovery.

  A recently proposed 533-acre timber harvest in the state’s largest DSF (Caspar 500 THP) provides a tangible case in point. The plan would have only reduced the forest density from 498 to 483 trees per acre (a 3% reduction).  A true restoration-focused thinning consistent with management practices envisioned by AB 2494 would have reduced the value to 275 trees per acre (a 45% reduction), resulting in a forest with much greater diversity in tree sizes, lower fire risk, and greater DOCSS.

Intensifying management to boost forest productivity can also come at a cost to biodiversity. When productivity gains are achieved through periodic thinning and removal of trees that would otherwise die from competition, that same thinning reduces the dead organic matter—snags and coarse woody debris—that provides wildlife habitat, diminishing both biodiversity and forest carbon stocks. A balanced approach is therefore essential. Globally, recognition of these biodiversity tradeoffs in high-yield forestry is driving a shift toward management that increases habitat availability through variable retention logging, continuous cover management, and the reintroduction of fire disturbance in landscapes where fire has long been suppressed. This is exactly the management approach AB 2494 seeks to implement.

The benefits of getting this balance right extend beyond carbon and biodiversity alone. The IPCC likewise recognizes that restoration forestry can support long-term livelihoods for communities, reduce the risk of forest conversion to non-forest uses such as settlement or cropland, and maintain land productivity—thereby reducing the risk of land degradation. Regarding socioeconomic benefits, a recent analysis found that shifting the management approach called for in AB 2494 would hold revenues constant while nearly tripling the number of jobs supported by California’s DSFs.

Taken together, these findings show that restoration forestry is not a single fixed prescription but a spectrum of practices whose climate and biodiversity outcomes depend heavily on how, where, and why they are applied. AB 2494 accounts for this complexity directly: by advocating for restoration forestry—including thinning to break up homogeneous stands and restore ecosystem function—while establishing DOCSS and wildfire resilience as co-equal management objectives, the bill preserves the flexibility land managers need to strike the appropriate balance between active management, like thinning and prescribed fire, and passive management, or the absence of intervention. Removing DOCSS as a stated objective would strip away one half of that essential balancing framework, leaving management decisions tilted toward the very high-yield, degradation-prone practices this section has shown to carry real climate and biodiversity costs.

C. DOCSS and restoration work together to provide effective climate resilience

DOCSS—achieved, as established in the previous section, through carefully planned techniques like prescribed burning and thinning—increases wildfire resilience, mitigates drought impacts, and prevents biodiversity loss. The phrase itself contains the word “durable” which is meant to convey the need to ensure that forests remain healthy and resilient. In terms of wildfire resilience, relevant management actions include retaining the largest and most fire-resilient trees and applying prescribed fire to reduce other fuel loads; thinning dense, young forests to encourage the growth of mature habitat characteristics; and protecting characteristics that may serve as important climate refugia for redwoods and associated species in the future. The state's draft 2026 Wildfire and Landscape Resilience Action Plan recognizes that healthy forests shaped by thinning and prescribed and cultural burning are more resilient to wildfire. 

DOCSS also helps mitigate the effects of drought and biodiversity loss—these objectives overlap and reinforce one another rather than compete. Redwood forests that store significant amounts of carbon are specifically associated with increased fog and cooler local temperatures, and could serve as microrefugia for other species under climate change. Mature, old-growth forests and individual large trees are similarly important for biodiversity, which again underscores the need for balance between active management and the protection of existing biodiversity value. This balance has measurable consequences: USFS lands in Oregon with lower fuel loads and older stands had less fire risk than private lands with higher fuel loads and younger stands, and protected forests across the western U.S. consistently burn less severely—fire severity is 1.45 times higher on private lands than on public lands. Due to the current mandate (which AB 2494 seeks to shift towards restoration)  for DSFs to demonstrate commercial logging to private timberland owners, it is no surprise that DSFs are managed much more closely to private lands than public lands. The differing outcomes for private versus public lands are not incidental to carbon storage but linked to it: lower fuel loads and older, structurally complex stands are themselves markers of durable onsite carbon storage in practice, since forests managed to retain large trees, canopy structure, and reduced surface fuels are the same forests accumulating and holding the greatest carbon stocks. Together, these findings make clear that DOCSS  is not a standalone climate goal but a resilience strategy in its own right, with measurable benefits for fire behavior, drought buffering, and species survival that HWP storage cannot replicate. 

Subsections A through C establish that DOCSS is not a symbolic or secondary objective but a scientifically grounded climate strategy. California's DSFs hold some of the state's most significant carbon reserves; restoration forestry, properly balanced with passive management, can grow and protect those reserves while avoiding the degradation risks of unsustainable harvest; and the resulting healthy, carbon-dense forests deliver wildfire resilience, drought mitigation, and biodiversity protection that carbon stored in harvested wood products simply cannot match. Any effort to weaken or remove DOCSS as a management objective—including proposals to substitute the broader "durable carbon storage"—would abandon this evidence base at precisely the moment California most needs it.

2. Durable carbon storage in harvested wood products from California’s DSFs is not an effective climate mitigation measure

Carbon stored in harvested wood products (HWP) is not an effective climate mitigation strategy. Elevating HWP carbon storage to a co-equal management objective in AB 2494—as opponents propose—would likely come at the expense of the bill's other management objectives, including biodiversity, climate resilience and adaptation, recreation, and ecosystem function, and conflict with other state policies and objectives.

This section examines the ineffectiveness of HWP carbon storage from four angles. Subsection A shows that HWP from DSFs—predominantly short-lived redwood products like decking and fencing—would not displace higher-emitting materials like steel or concrete in the way the substitution argument requires. Subsection B demonstrates that even under best-case assumptions, HWP's carbon storage contribution is minor and inconsistent compared to onsite forest carbon. Subsection C shows that standard carbon accounting routinely fails to include the full emissions generated in harvesting and transporting timber, meaning HWP's credited climate benefit is typically overstated. And Subsection D shows that climate change is destabilizing the forest regrowth rates that HWP's climate value depends on in the first place. Together, these factors make clear that carbon stored in HWP cannot support the same weight as DOCSS in AB 2494's management framework.

A. Unclear whether HWP from DSFs replace higher-emitting products

Sustainable forestry can function as a net carbon sink, but only under two conditions: HWP must displace higher-emitting products such as concrete or steel in long-term building structures, and forests must regrow quickly enough to offset the initial carbon losses from harvesting. Even where these conditions are met, the evidence suggests the climate benefit comes primarily from displacement rather than storage—research indicates that the substitution effect of avoiding fossil-intensive materials outweighs the carbon actually stored in wood products over the long term. And storage itself is a moving target: carbon stored in wood products affects atmospheric concentration only through changes in the size of the wood products pool as a whole—that is, the balance between new wood products entering service and old wood products decaying or burning and releasing their stored carbon back into the atmosphere. For HWP to function as durable storage, the creation of new, long-lasting wood products must reliably outpace the decay of old ones. Yet the most recent CARB data shows carbon input into the HWP pool barely exceeding carbon loss—a margin far too thin to support HWP as a reliable, durable carbon sink. 

Even setting aside this structural uncertainty, a significant amount of HWP from California's DSFs does not displace concrete or steel in the way the substitution argument requires. The vast majority of wood harvested from DSF is redwood and white fir. Redwood—apart from old-growth material—is not well suited to home construction. Instead, it is used primarily for decks, fencing, furniture, and other decorative applications: products with shorter service lives and no claim to meaningfully displacing steel or concrete in permanent structures. Data from the NWL Carbon Inventory shows that in domestic HWP carbon is primarily stored in housing and construction products, though there is no analysis provided on how long these products may last. Purported "permanent" storage in housing and construction lumber tends not to be particularly permanent in practice: wood products that do enter homes and other structures are typically burned or landfilled at the end of the structure's usable life, averaging 70 to 100 years—a fraction of the multi-century storage timescales that durable climate mitigation requires. Moreover, certain uses of HWP—for exterior applications and decking and fencing in particular—are contrary to the direction of state fire resilience policy, which is encouraging fire-resistant building materials.

By contrast, the restoration forestry encouraged under AB 2494 is well suited to supplying mass timber, a genuinely durable, high-displacement substitute for steel and concrete construction. And DOCSS does not foreclose this potential: as established in Section I, restoration forestry achieves DOCSS in part through the harvest of smaller-diameter trees—precisely the feedstock that mass timber and other restoration forestry products require. HWP and DOCSS are not, therefore, competing paths to the same goal; where wood products do offer genuine climate benefit, it is through the kind of restoration-based harvest DOCSS already accommodates, not through elevating HWP to a separate, co-equal objective built on far less certain footing.

B. Even if HWP serve as a carbon sink, they are not significant enough to prioritize alongside DOCSS in DSF management objectives

Even under a best-case scenario, the global potential of HWP as a carbon sink is minor: a comprehensive analysis of HWP carbon storage potential consistently finds it offsets less than 1% of global emissions. This minor contribution is reflected in California's own data as well. Forest land—including both soil and biomass—comprises 56.4% (2,800 MMt) of California's total carbon stock, while HWP accounts for just 3.8% (250 MMt). State-owned lands, moreover, have historically contributed only ~1% of domestic harvest inflows, averaging 0.04 MMT annually prior to 2001, dropping to 0.01 MMT between 2001 and 2013, returning to 0.04 MMT from 2014 through 2021, and rising somewhat in 2022.  Even accounting for this contribution, domestic HWP consumption has produced inconsistent climate benefit: annual CO2e removals averaged 18.7 MMT from 2001–2013 but fell to 6.5 MMT from 2014–2022, and the pool actually became a net emissions source during 2009–2011 and again in 2021–2022, averaging –4.3 MMT and –3.1 MMT per year in those periods, respectively. 

None of this is to say that HWP store no carbon at all—that is not AB 2494's claim, nor this paper's. Rather, the point is narrower and more precise: DOCSS should be prioritized because it is a substantially larger, more effective, and more consistent climate mitigation and resilience strategy than carbon stored in HWP, which even by its own advocates' best estimates remains a minor, volatile, and at times net-negative contributor to California's carbon accounting. A management framework that treats HWP as co-equal to DOCSS would elevate a marginal and unreliable carbon strategy to the same status as one that is substantial and consistent—exactly the kind of miscalibration AB 2494's original, unamended language was designed to avoid.

C. Emissions in timber harvest are not always effectively tracked

The relative ineffectiveness surrounding HWP as a climate mitigation strategy is compounded by a further problem: the emissions generated in bringing timber to market are routinely and substantially undercounted. These emissions arise at every stage of the process—cutting, yarding, unusable tree removals, slash burning, transport, milling, manufacturing, distribution to the marketplace, and construction waste—yet standard carbon accounting frequently fails to capture them in full. Additional uncounted carbon is lost due to erosion and degradation of soil quality as a result of logging operations. Many wood-harvest carbon accounting methods substantially understate emissions by improperly crediting new harvests with forest regrowth that would have occurred regardless of harvest activity, while other harvest-related emissions, including slash management and transport, are frequently omitted from standard accounting altogether. Considering these factors, only roughly 15% of the carbon in a harvested tree makes it into the final wood product. California's own accounting is not immune to this problem: the NWL Carbon Inventory does not appear to account for these upstream and process emissions in its HWP carbon stock contributions, tracking only end-of-life emissions instead.

Essentially, this means the carbon "credited" to HWP in California's own accounting overstates its true climate benefit, since it omits real emissions incurred well before a wood product reaches the end of its life. Any policy that treats HWP as a co-equal carbon storage objective is therefore built on an accounting foundation that is, by its own limitations, incomplete.

D. Under climate change, rates of forest regrowth and the meaning of “sustainability” must be reconsidered

The case for HWP as durable carbon storage depends on another critical assumption: that harvested forests will regrow quickly enough to replace the carbon lost to harvest. Even under historical conditions, regrowth periods – e.g. 100-200 years in the case of second-growth redwood trees – are far too long given the need to address climate change impacts manifesting now. Under climate change, that assumption is increasingly inaccurate. Sierra Nevada forests are already showing reduced growth rates due to warming temperatures, and vegetation growth is slowing globally—a trend consistent with a large and growing body of scientific literature on climate-related forest responses. California's own DSFs are not exempt from this pattern: peer-reviewed research funded by CAL FIRE across three DSFs—Jackson, Las Posadas, and Soquel—confirms a pronounced trend toward slowing tree growth over the past quarter century. Climate change is altering not just growth rates but forest composition and range: suitable habitat for coast redwoods is shifting northward and westward, meaning the very forests HWP sustainability arguments depend on may not persist, in kind or in place, long enough to complete the regrowth cycle those arguments assume. These are not abstract or future risks. Boggs Mountain DSF experienced a severe wildfire in 2015—a concrete illustration of how quickly climate-driven disturbance can outpace assumptions of steady, predictable regrowth.

This evidence shows that the premise underlying HWP as a climate mitigation strategy—that harvested forests reliably and predictably regrow—can no longer be taken for granted, and must be accounted for when weighing the potential climate benefits of carbon stored in HWP against the relative certainty of DOCSS. The IPCC 2019 Special Report on Climate Change and Land reaches the same conclusion, cautioning that sustainable forest management must anticipate the impacts of climate change on future tree growth, mortality, and disturbance when designing climate mitigation and adaptation strategies.  If even the IPCC's guidance on sustainable forestry treats future growth as uncertain rather than assured, AB 2494 cannot afford to treat it otherwise.

Conclusion

This returns us to the central uncertainty this paper has traced throughout: carbon stored in HWP compared to carbon stored in healthy, standing forests. The IPCC's 2019 Special Report captures why this uncertainty is so consequential: whether forest harvest and biomass use ultimately reduce net atmospheric carbon depends on carbon losses during and after harvest, the rate at which forests regrow, how long harvested wood retains its carbon in long- versus short-lived products, and the emissions actually avoided by substituting wood for other materials. As this paper has shown, each of these variables remains uncertain when applied to California's DSFs. Carbon storage is also not the only benefit at stake. Healthy, intact forests provide a wide range of value beyond carbon storage and sequestration alone—benefits that a harvested and processed wood product cannot replicate regardless of how its carbon is accounted for.

Carbon stored in HWP, in short, is difficult to measure, riddled with structural uncertainty, and even under the most generous assumptions falls far short of the carbon storage and sequestration achieved by standing forests. DOCSS belongs in AB 2494 not as a preference but as a matter of evidence—one co-equal management objective among several, standing alongside biodiversity conservation and habitat, climate resiliency and adaptation, ecosystem function, recreation, watershed health, wildfire resilience, and the DSFs' role as a living laboratory for ecological research and showcasing the latest thinking on climate friendly forest management. Its inclusion directly advances the state's existing climate policies, and on that basis alone, Governor Newsom should sign AB 2494 into law as introduced.