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The California Air Resources Board’s US Forest offset protocol underestimates leakage
Abstract
Analysis of projects generating 80% of total offset credits issued by the California Air Resources Board's (ARB) U.S. Forest offset protocol finds that 82% of these credits likely do not represent true emissions reductions due to the protocol's use of lenient leakage accounting methods. The U.S. Forest protocol has generated 80% of the offset credits in California's cap-and-trade program. The total quantity of emissions allowed because of this over-crediting equals approximately 80 million tons of CO 2 , which is one third of the total expected effect of California's cap-and-trade program during 2021 to 2030 (ARB 2017). Leakage, in the context of the protocol, occurs when a reduction in timber harvesting at a project site causes an increase in timber harvesting elsewhere to meet timber demand. The way ARB's protocol accounts for leakage when calculating the number of credits awarded has three serious problems. First, the protocol uses a 20% leakage rate when a rate of 80% or higher is supported by published studies of leakage rates from reduced timber harvesting in the United States (Gan & McCarl 2007, Wear & Murray 2004). Using an unsupported low rate results in over-crediting. Second and more importantly, there is an inconsistency between the timing of when increases in on-site carbon storage and releases due to leakage are accounted for in the protocol's methods. Most improved forest management projects assume and credit a large reduction in timber harvesting in the first year of the offset project, but deduct the associated leakage over 100 years. This outcome is physically inconsistent, as it assumes the forest would be harvested in the first year for the purpose of giving credit but assumes harvesting would be spread out over 100 years for the purpose of reducing credits to account for leakage. As a result, most forest offset projects begin in greenhouse gas debt; project landowners generate offset credits that allow emitters in California to emit more than the state's emissions cap today, in exchange for promises that their lands will continue to increase their storage of carbon over 100 years. Third, it is unclear whether the protocol requires forestland owners to increase carbon stocks to cover leakage for 25 years or for 100 years. The ambiguity relates to whether forestland owners are required to continue to maintain on-site growth to cover the impacts of leakage after the end of the project's 25-year crediting period. If forestland owners are only required to account for leakage for 25 years, participating projects could result in no net increase in carbon storage over 100 years compared to the baseline scenario. The below table presents the actual emissions reductions achieved by projects under the protocol under different assumptions, reported as proportions of the credits already issued. For example, the cell on the upper left (100%) represents the assumptions underlying current policy. If these
... Peer-reviewed and non-peer-reviewed studies of IFM offset projects and protocols have shown evidence of over-crediting and non-conservative methodological rules. Studies of the California Air Resources Board (ARB) forest offset protocol found that the protocol is likely to significantly over-generate credits due to its methods for assessing project baselines (Badgley et al., 2022b;Coffield et al., 2022), leakage (Haya, 2019), and risk of reversal (Anderegg et al., 2020;Badgley et al., 2022a), as well as to create incentives counter to long term carbon stability in fire-prone areas (Herbert et al., 2022). Several peer reviewed and investigative case study analyses of projects using different IFM protocols identified substantial over-crediting (van Kooten et al., 2015;Elgin, 2020;Koberstein and Applegate, 2021). ...
... In addition to market leakage rates, the timing of the leakage deduction can have large effects on the number of credits issued. Prior research found that the ARB and CAR-U.S. protocols tend to greatly over-credit at the start of each project, due to a timing mismatch in the construction of the baseline scenario (Haya, 2019;Haya and Stewart, 2019). Most ARB IFM projects start with carbon stocks far above estimated baseline levels; initial carbon stocks 40-50% higher than baseline levels are typical (Haya, 2019). ...
... Prior research found that the ARB and CAR-U.S. protocols tend to greatly over-credit at the start of each project, due to a timing mismatch in the construction of the baseline scenario (Haya, 2019;Haya and Stewart, 2019). Most ARB IFM projects start with carbon stocks far above estimated baseline levels; initial carbon stocks 40-50% higher than baseline levels are typical (Haya, 2019). This is based on the assumption that without the offset program, timber would be aggressively harvested, reducing onsite carbon stocks substantially. ...
Improved forest management (IFM) has the potential to remove and store large quantities of carbon from the atmosphere. Around the world, 293 IFM offset projects have produced 11% of offset credits by voluntary offset registries to date, channeling substantial climate mitigation funds into forest management projects. This paper summarizes the state of the scientific literature for key carbon offset quality criteria—additionality, baselines, leakage, durability, and forest carbon accounting—and discusses how well currently used IFM protocols align with this literature. Our analysis identifies important areas where the protocols deviate from scientific understanding related to baselines, leakage, risk of reversal, and the accounting of carbon in forests and harvested wood products, risking significant over-estimation of carbon offset credits. We recommend specific improvements to the protocols that would likely result in more accurate estimates of program impact, and identify areas in need of more research. Most importantly, more conservative baselines can substantially reduce, but not resolve, over-crediting risk from multiple factors.
... The quality of carbon credits hinges on the robustness of these standards and choices made by project developers. Potential issues compromising additionality and quantification include flexibility for project developers to pick favourable data or make unrealistic assumptions 2,3,6,8,9,23 , adverse selection 4,13 , and use of outdated data or inappropriate methodological approaches in the standards 2,3,6,9,11,15,16,24,25 . There is also considerable debate on the appropriateness of claims made in association with carbon credits and whether the use of carbon credits hinders or accelerates mitigation efforts. ...
... Other studies of ARB IFM projects have found additional sources of over-crediting, suggesting that even if some projects changed their forest management practices, the emission reductions or removals would still likely be overestimated due to methods for assessing leakage 25 and for quantifying reversal risk and associated contribution of credits into the insurance buffer pool 13 . No studies to date have conducted quantitative assessments of the quality of credits under other IFM protocols. ...
Carbon markets play an important role in firms’ and governments’ climate strategies. Carbon crediting mechanisms allow project developers to earn carbon credits through mitigation projects. Several studies have raised concerns about environmental integrity, though a systematic evaluation is missing. We synthesized studies relying on experimental or rigorous observational methods, covering 14 studies on 2346 carbon mitigation projects and 51 studies investigating similar field interventions implemented without issuing carbon credits. The analysis covers one-fifth of the credit volume issued to date, almost 1 billion tons of CO2e. We estimate that less than 16% of the carbon credits issued to the investigated projects constitute real emission reductions, with 11% for cookstoves, 16% for SF6 destruction, 25% for avoided deforestation, 68% for HFC-23 abatement, and no statistically significant emission reductions from wind power and improved forest management projects. Carbon crediting mechanisms need to be reformed fundamentally to meaningfully contribute to climate change mitigation.
... Uncertainty and high cost of typical commercial forest carbon offset protocols are unresolved [1][2][3][4][5][6], impeding widespread adoption and expansion of forest conservation projects. The main endeavor of commercial forest carbon offset trading is to assist landowners with the conservation and restoration of forests based on the net carbon sequestration and carbon credit sales for a project [7,8] while verifiably reducing net emissions. ...
... Details of model revisions and results were not provided, calling the validity of model results into question; (3) The Howland NEE and soil GHG records, advancing annually from 1996 to 2021, were available to CARB-CAR project owners, operators, and third-party verifiers (38,40,41,43,44,45,58,59,60) overlapping with the supply chain process from 2013 to 2019 culminating in serialized CARB verified offsets according to the AB32 mandate [70]. The Howland US-Ho1 NEE data were not reported as an independent check of the CARB-CAR annual results, a comparison that would have constrained the natural ranges for carbon sequestration offering an opportunity to proscriptively avoid CARB-CAR forest carbon sequestration uncertainties; (4) The Howland CARB-CAR project reporting exhibits errors and lapses in recordation, similar to those reported previously [1], including numerical errors, changes in reporting format from annual to discretionary mixed time intervals, and non-standard model operations resulting in uncertain values; and, (5) The raw data and detailed model outputs for the CARB-CAR projects have not been made available to the public, limiting collaboration and external verification of the project results. Instead, the CARB-CAR data and information are housed on personal computers with no central repository (Supplement Table S5, Item 10). ...
Forest carbon sequestration is a widely accepted natural climate solution. However, methods to determine net carbon offsets are based on commercial carbon proxies or CO2 eddy covariance research with limited methodological comparisons. Non-CO2 greenhouse gases (GHG) (e.g., CH4, N2O) receive less attention in the context of forests, in part, due to carbon denominated proxies and to the cost for three-gas eddy covariance platforms. Here we describe and analyze results for direct measurement of CO2, CH4, and N2O by eddy covariance and forest carbon estimation protocols at the Howland Forest, ME, the only site where these methods overlap. Limitations of proxy-based protocols, including the exclusion of sink terms for non-CO2 GHGs, applied to the Howland project preclude multi-gas forest products. In contrast, commercial products based on direct measurement are established by applying molecule-specific social cost factors to emission reductions creating a new forest offset (GHG-SCF), integrating multiple gases into a single value of merit for forest management of global warming. Estimated annual revenue for GHG-SCF products, applicable to the realization of a Green New Deal, range from ~12,000,000 USD for extrapolation to 40,000 acres in 2040, assuming a 3% discount rate. In contrast, California Air Resources Board compliance carbon offsets determined by the Climate Action Reserve protocol show annual errors of up to 2256% relative to eddy covariance data from two adjacent towers across the project area. Incomplete carbon accounting, offset over-crediting and inadequate independent offset verification are consistent with error results. The GHG-SCF product contributes innovative science-to-commerce applications incentivizing restoration and conservation of forests worldwide to assist in the management of global warming.
... California involves forestry in its ETS scheme through an offsets protocol. While there are several ways to earn offset credits in the California scheme, 80% of these come from the US Forests Protocol which is what forestry falls under (Haya 2019). Three types of activity are eligible for offset credits under the current ETS. ...
... Finally, the protocol is ambiguous when it comes to whether forest owners must maintain forest growth over 25 years or 100 years to cover the leakages, which results in forest owners able to receive offset credits with no ultimate change in carbon storage. To fix this, the policy brief suggests that the protocol needs to be adjusted with a leakage rate of 80% and both offsets and leakages calculated on a yearly basis (Haya 2019). However, the policy brief is contested by several other academics as well as the California Air Resources Board who oversee the ETS. ...
This paper aims to explore the New Zealand Emissions Trading Scheme (NZ ETS) in detail, from a forestry-centric perspective and to offer suggestions for further reform. The paper will aim to provide a
comprehensive examination of both the existing and the proposed New Zealand schemes centred around the forestry sector. It will also investigate the California-Québec scheme and the possibility of linking
the two schemes and the implications of linkage for the forestry sector in New Zealand. Finally, it will investigate the reasons for New Zealand’s relative lack of effectiveness as well as exploring options from both
California-Québec and beyond to expand the scheme. It is hoped that this paper has particular relevance given the importance of forestry within New Zealand’s economy and given the discussions that are currently
happening around potentially linking the California-Québec ETS with the NZ ETS.
... Lowering the Common Practice value relative to actual standing carbon stock for Howland Forest, incorrectly attributes historic carbon (e.g., unknown years of cumulative forest growth prior to the project) to a single vintage initial year of carbon sequestration. In effect, this results in higher initial year crediting, consistent with independent error analyses of similar CARB-CAR projects (Dunlop, Winner & Smith, 2019;Haya, 2019;Haya et al., 2016). ...
... The well-established anomalous nature of CARB-CAR CA projects (−1,163.2 ± 1,880, n = 31), do not require site-specific overlapping NEE data for comparison with NEE1,2 population data to conclude that the CA site data do not reflect known ranges for NEE and are arguably invalid, consistent with systemic errors noted for Howland Forest (e.g., 31 cases of anomalous initial year values, Table 1). Cases for invalidation based on problems of additionality and leakage (Dunlop, Winner & Smith, 2019;Haya, 2019) as well as questions raised by extension of CARB-CAR protocols to REDD+ tropical forests ('Survey of CARB-CAR Linked Protocols', endnote 5) (California Air Resources Board, 2018b), underscore the need and importance of resolving CARB-CAR protocol uncertainties. ...
The commercial asset value of sequestered forest carbon is based on protocols employed globally; however, their scientific basis has not been validated. We review and analyze commercial forest carbon protocols, claimed to have reduced net greenhouse gas emissions, issued by the California Air Resources Board and validated by the Climate Action Reserve (CARB-CAR). CARB-CAR forest carbon offsets, based on forest mensuration and model simulation, are compared to a global database of directly measured forest carbon sequestration, or net ecosystem exchange (NEE) of forest CO 2 . NEE is a meteorologically based method integrating CO 2 fluxes between the atmosphere, forest and soils and is independent of the CARB-CAR methodology. Annual carbon accounting results for CAR681 are compared with NEE for the Ameriflux site, Howland Forest Maine, USA, (Ho-1), the only site where both methods were applied contemporaneously, invalidating CARB-CAR protocol offsets. We then test the null hypothesis that CARB-CAR project population data fall within global NEE population values for natural and managed forests measured in the field; net annual gC m ⁻² yr ⁻¹ are compared for both protocols. Irrespective of geography, biome and project type, the CARB-CAR population mean is significantly different from the NEE population mean at the 95% confidence interval, rejecting the null hypothesis. The CARB-CAR population exhibits standard deviation ∼5× that of known interannual NEE ranges, is overcrediting biased, incapable of detecting forest transition to net positive CO 2 emissions, and exceeds the 5% CARB compliance limit for invalidation. Exclusion of CO 2 efflux via soil and ecosystem respiration precludes a valid net carbon accounting result for CARB-CAR and related protocols, consistent with our findings. Protocol invalidation risk extends to vendors and policy platforms such as the United Nations Program on Reducing Emissions from Deforestation and Forest Degradation (REDD+) and the Paris Agreement. We suggest that CARB-CAR and related protocols include NEE methodology for commercial forest carbon offsets to standardize methods, ensure in situ molecular specificity, verify claims of carbon emission reduction and harmonize carbon protocols for voluntary and compliance markets worldwide.
... The degree of variation is concerning and points to a need to fundamentally overhaul leakage assessment for project-level accounting, for both activity shifting and market leakage at local to global scales. However, for US projects, it should be possible to develop more regionally representative default values that can be established and integrated into protocols based on currently available data (Haya, 2019). Furthermore, protocols for improved forest management that require no or minimal reduction in harvest could better account for market leakage (Haya, Evans, et al., 2023;Walker et al., 2023). ...
Forests have substantial potential to help mitigate climate change. Private finance channeled through carbon credits is one way to fund that mitigation, but market‐based approaches to forest carbon projects have been fraught to date. Public skepticism of forest carbon markets signals a need to closely scrutinize the system for certifying carbon credits. We rigorously reviewed and scored new and existing protocols for the voluntary and North American compliance carbon markets. We included protocols for forest projects engaging in improved forest management, afforestation/reforestation, and avoided planned forest conversion. Most protocols score poorly overall, and none were assessed as robust. Only one new protocol that had yet to issue credits at the time of our evaluation was assessed as satisfactory, owing to improvements in the approach to additionality demonstration. We conclude that existing protocols do not ensure carbon credits are consistently real, high‐quality, and accurately represent 1 tonne of avoided, reduced, or removed emissions. We offer recommendations for how protocols can be strengthened using existing data and new tools to promote reliably high‐quality credits. Continuing to rely on the status quo without such investments is a serious risk to climate change mitigation, and in our estimation, these proposed improvements would increase the likelihood that forests carbon projects can deliver their promised climate mitigation benefits.
... This possibility may arise, for instance, if a greater land area is set aside for grasslands or forests and if the prices of cereal crops increase. For instance, in the Compliance Offset Program in the California Cap and Trade Program, leakage in forestry-based projects reached levels as high as 80% [52], and in the Conservation Reserve Program in the U.S., which is aimed at reducing soil erosion and improving water quality, leakage is estimated to constitute 20% of the conserved area [53]. Voluntary markets should be designed so that they generate extra credits to counteract leakage if it is assessed as a relevant risk. ...
In this study, we examine how to enhance the climate integrity of carbon credits from carbon farming practices. The key requirements for climate integrity include permanence, additionality, and measurement and verification. Farmers are typically willing to make carbon contracts for a finite time only in voluntary markets or with the government and receive carbon credits to sell as offsets. This contradicts the requirement of the permanence of carbon sequestered in soils. To solve this problem and to facilitate greater participation by farmers in carbon sequestration, we show how temporary contracts can be made to address the issue of permanence by using offset ratios. The notion of the offset ratio refers to the share of one emission unit that one unit of temporary sequestered carbon replaces. Thus, the offset ratio transforms temporary sequestration to permanent emissions reductions. We propose the use of a discounting method to calculate the offset ratio. The ratio varies with the carbon contract length, employed discount rate, and assumptions about the evolution of the soil carbon stock. We apply this approach to cultivating catch crops for carbon sequestration on a north‒south gradient in Finland, Denmark, and France. We show that the offset ratio approach works well for every selected country. Carbon farming contracts are profitable for farmers provided that revenue under the contract exceeds that in the baseline. Profitability is highly dependent on catch crop cost, annual increase in soil carbon, and the discount rate. We apply offset ratios to assess the climate integrity of some existing crediting programs and find that the discounting method yields a lower offset ratio in almost all cases yielding a lower number of credits than launched in these programs.
... Studies of offset project quality have documented substantial excess crediting (as much as 13 times from single factors) from improved forest management 5,6 , avoided deforestation 7,8 and the United Nations system 9,10 . Over-crediting is harmful to effective climate action, the buyer and the cookstove sector. ...
Cookstove carbon offset projects can progress multiple Sustainable Development Goals (SDGs), including climate, energy, health, gender, poverty and deforestation. However, project emission reductions must be accurately or conservatively estimated to avoid undermining climate action and long-term SDG financing. Here we conduct a comprehensive, quantitative, quality assessment of offsets by comparing five cookstove methodologies with published literature and our own analysis. We find misalignment, in order of importance, with fraction of non-renewable biomass, firewood–charcoal conversion, stove adoption, stove usage, fuel consumption, stacking (using multiple stoves), rebound and emission factors. Additionality, leakage, permanence and overlapping claims require more research. We estimate that our project sample is over-credited 9.2 times. Gold Standard’s metered methodology, which directly monitors fuel use, is most aligned with our estimates (1.5 times over-credited) and has the largest potential for emission abatement and health benefit. We provide recommendations to align methodologies with current science and SDG progress.
... Haya 10,20 estimates that for the compliance period between 2021 and 2030, offsets could represent more than 50% of the reductions attributable to the cap-and-trade program. Despite these legal requirements and the importance of IFM projects to California's climate goals, growing empirical evidence suggests that offsets in this program are not accurately credited for baselines, additionality, and leakage, leading to over-crediting, and non-additional due to asymmetric information and adverse selection 12,17,[21][22][23][24] . ...
Carbon offsets are widely promoted as a strategy to lower the cost of emission reductions, but recent findings suggest that offsets may not causally reduce emissions by the amount claimed. In a compliance market, offsets increase net emissions if they do not reflect real emission reductions beyond the baseline scenario. Few studies have examined the additionality of forest carbon offsets within California’s U.S. Forest Projects compliance offset protocol, one of the largest forest offset programs in the world. Here we examine additionality in California’s offset protocol. Since 2012, most of California’s offset credits (84%) have been awarded to improved forest management projects. Using a database of improved forest management project characteristics, locations, and remotely sensed forest disturbance data indicative of management activity, we find that projects have been primarily allocated to forests with high carbon stocks (127% higher than regional averages) and low historical disturbance (28% less disturbance than regional averages since 1985). A matching and panel regression analysis failed to show additionality, as project creation did not significantly lower disturbance rates 3 and 5 years after project implementation relative to similar non-project lands. These results indicate that California’s forest offset protocol may contribute to an increasingly large carbon debt.
... We emphasize that the unaccounted positive emissions represented by ecosystem respiration (R eco comprised of heterotrophic and autotrophic respiration), on an hourly to annual basis, triggers automatic debits to the net forest carbon project offset ledger resulting in unequivocal over-crediting of offsets in addition to any other sources of over-credit error (e.g., above ground carbon accounting, Badgley et al., 2021). Consequently, CFCP project offsets, unless proven otherwise, should be adjusted downward based on corrective measurements, or voided as the basis for valid carbon transactions, as previously reported (Badgley et al., 2021;Bautista et al., 2021;Haya, 2019;Marino et al., 2019;Marino et al., 2021). ...
The validity of forest carbon offsets is increasingly called into question. However, despite the use of commercial forest carbon protocols (CFCPs) for more than two decades, claiming ∼566 MMtCO2e and a market value of ∼USD $15.7 billion, comparative analysis and quality assurance of CFCP methodology and offset results are limited. In this study, five widely used biometric-based CFCPs are characterized and compared with results of directly measured CO2 by eddy covariance, a meteorological method integrating vertical fluxes of forest and soil carbon and the only alternative non-biometric source of net forest carbon sequestration data available. We show that CFCPs share a structural feature delimiting forest carbon values by zero-threshold carbon accounting (gC m⁻² y⁻¹ or d⁻¹ ≤ 0), confirming reported forest carbon uncertainty, elucidating the data gap across CFCPs, and emphasizing the need for urgent improvement. The CFCP pattern of values is in contrast to known natural emissions of global forest CO2 exchange that is based on direct measurement, obviating a fundamental biological constraint on net forest carbon storage (i.e., soil efflux, ecosystem respiration). Exclusion of forest CO2 sources to the atmosphere precludes net carbon accounting, resulting in unavoidable over-credit of CFCP project offsets. CFCP carbon results are significantly different from global forest CO2 net ecosystem exchange population results (FluxNet2015 gC m⁻²) at the 95% to 99.99% confidence levels, inferring an annual median error of ∼247% (gC m⁻²), consistent with over-crediting. Given the urgency in reliably reducing CO2 emissions and achievement of net-zero and carbon neutral goals, direct CO2 measurement provides a quality-assured alternative method for commercial forest carbon products with the potential to harmonize global markets, catalyzing the role of forests in managing climate change through nature-based solutions.
... Leakage: When offsets pay for forest conservation, production of the commodities most responsible for forest loss-palm oil, soy, cattle, minerals, and pulpwood-can be moved to less regulated jurisdictions as long as there is demand for those commodities (Wear and Murray 2004;Alix-Garcia and Gibbs 2017;Ingalls et al. 2018;Haya 2019). Nonadditionality: Offsets payments are based on guesses about how much carbon storage would be lost or gained if a project did not happen; credits are often issued for activities that would have occurred regardless of any projects or policies financed by offset-credit sales (Mertz et al. 2018;Song 2019;West et al. 2020). ...
Offsetting is widely embraced as a market-based solution to global warming. Governments, universities, and businesses of all sorts have pledged to achieve “net zero” greenhouse gas emissions partly or entirely through offsetting projects, many of which rely on so-called nature-based solutions (NBSs). Offsets are meant to compensate for damage caused by emissions from one place by absorbing or preventing the release of an equivalent amount somewhere else. At best, offsetting results in no change in total emissions, but as theory predicts and experience shows, that best result is rarely attainable. Meanwhile, both land-based and industrial offsets legitimize continued emissions. There is active debate in Paris-pact talks and in climate politics more broadly over how much fossil-fuel industries and industrial countries will be allowed to delay real climate action by representing offsets as if they were emissions reductions. The American Association of Geographers should not contribute to this illusion by endorsing offsetting. Instead we should take steps to reduce our own emissions and speak out clearly when our work has bearing on policy decisions and public perceptions about the climate crisis.
... We emphasize that the unaccounted positive emissions represented by ecosystem respiration (Reco comprised of heterotrophic and autotrophic respiration) triggers automatic debits to the net forest carbon project offset ledger resulting in unequivocal overcrediting of offsets [11], [31], [56]. Consequently, CFCP project offsets, unless proven otherwise, should be adjusted downward based on corrective measurements, or voided as the basis for valid carbon transactions, as previously reported [11], [34], [97]. Referring to Figure 3.A,B shows results for CFCPs compared with NEE (gC m -2 y -1 ) plotted as probability histograms (A) NEE (blue), CARB-CAR (orange), ACR (gray), CDM (green), and (B) NEE (gC m -2 d -1 ) (blue), VERRA (yellow). ...
Despite the use of commercial forest carbon protocols (CFCPs) for more than two decades, claiming ~566 MMtCO2e and a market value of ~USD $15.7 billion, comparative analysis of CFCP methodology and offset results is limited. In this study, five widely used biometric-based CFCPs are characterized, and common characteristics and differences are identified. CFCP claims of net forest carbon sequestration are compared with results of directly measured CO2 by eddy covariance, a meteorological method integrating gross vertical fluxes of forest and soil carbon, and the only alternative non-biometric source of net forest carbon sequestration data available. We show here that CFCPs share a structural feature delimiting forest carbon values by zero-threshold carbon accounting (gC m-2 ≤ 0), a pattern opposite to natural emissions of forest CO2 exchange based on direct measurement and a fundamental biological constraint on net forest carbon storage (i.e., soil efflux, ecosystem respiration). Exclusion of forest CO2 sources to the atmosphere precludes net carbon accounting, resulting in unavoidable over-crediting of CFCP project offsets. CFCP carbon results are significantly different from global forest CO2 net ecosystem exchange population results (FluxNet2015 gC m-2) at the 95% to 99.99% confidence levels, inferring an annual median error of ~247% (gC m-2), consistent with over-crediting. Direct CO2 measurement provides an urgently needed alternative method for commercial forest carbon products that has the potential to harmonize global markets and catalyze the role of forests in managing climate change through nature-based solutions.
... The unaccounted positive emissions represented by ecosystem respiration (Reco comprised of heterotrophic and autotrophic respiration) triggers automatic debits to the net forest carbon project offset ledger resulting in overcrediting of offsets [7], [20], [49]. Consequently, CFCP project offsets, unless proven otherwise, should be adjusted downward, or voided as the basis for valid material transactions, as previously reported [7], [9], [62]. Fig. 3.A-D clearly shows and confirms that the probability histograms for CFCPs exclude values ≤ 0 (gC m -2 y -1 or d -1 ) for all protocols, with few isolated outliers as noted in the histograms, consistent with the dispersion and statistical analysis results (Fig. 2, Table 2). ...
Despite the use of commercial forest carbon protocols (CFCPs) for more than two decades, claiming ~566 MMtCO2e and a market value of ~USD $15.7 billion, comparative analysis of CFCP methodology and offset results is limited. In this study, five widely used biometric-based CFCPs were characterized, and common characteristics and differences were identified. CFCP claims of net forest carbon sequestration are compared with results of directly measured CO2 by eddy covariance, a meteorological method integrating gross vertical fluxes of forest and soil carbon, and the only alternative non-biometric source of net forest carbon sequestration data available. We show here that CFCPs share a structural feature delimiting forest carbon values by zero-threshold carbon accounting (gC m-2 ≤ 0), a pattern opposite to natural emissions of forest CO2 exchange based on direct measurement and a fundamental biological constraint on net forest carbon storage (i.e., soil efflux, ecosystem respiration). Exclusion of forest CO2 sources to the atmosphere precludes net carbon accounting, resulting in unavoidable over-crediting of CFCP offsets. CFCP carbon results are significantly different from global forest CO2 net ecosystem exchange population results (FluxNet2015 gC m-2) at the 95% to 99.99% confidence levels, inferring an annual median error of ~247% (gC m-2), also consistent with over-crediting. Direct CO2 measurement provides an alternative method for commercial forest carbon products, has the potential to harmonize global markets, and catalyze the role of forests in managing climate change through nature-based solutions.
... California offsets are limited to the US, but a series of policy and scholarly papers raises questions about their additionality. One study estimates that 82% of the credits generated through improved forestry management do not represent genuine reductions (Haya 2019). Another suggests that Californian offset protocols have reduced, but not eliminated, problems of over-crediting. ...
Carbon pricing has been hailed as an essential component of any sensible climate policy. Internalize the externalities, the logic goes, and polluters will change their behavior. The theory is elegant, but has carbon pricing worked in practice? Despite a voluminous literature on the topic, there are surprisingly few works that conduct an ex-post analysis, examining how carbon pricing has actually performed. This paper provides a meta-review of ex-post quantitative evaluations of carbon pricing policies around the world since 1990. Four findings stand out. First, though carbon pricing has dominated many political discussions of climate change, only 37 studies assess the actual effects of the policy on emissions reductions, and the vast majority of these are focused on Europe. Second, the majority of studies suggest that the aggregate reductions from carbon pricing on emissions are limited—generally between 0% and 2% per year. However, there is considerable variation across sectors. Third, in general, carbon taxes perform better than emissions trading schemes (ETSs). Finally, studies of the EU-ETS, the oldest ETS, indicate limited average annual reductions—ranging from 0% to 1.5% per annum. For comparison, the IPCC states that emissions must fall by 45% below 2010 levels by 2030 in order to limit warming to 1.5 °C—the goal set by the Paris Agreement (Intergovernmental Panel on Climate Change 2018). Overall, the evidence indicates that carbon pricing has a limited impact on emissions.
... For government policy processes to take up the most recent scientific understanding of perma-nence and other relevant risks, policy-makers need to be aware of and open to new information. The relationship between policy-makers and scientific information is complex (127) and may be most challenging when new information raises fundamental questions about policymakers' prior assumptions (128). Frequent and formal review mechanisms within F-NCS policies and the willingness of policy-makers to consider new information-especially information critical of current practices-will ensure the uptake of new scientific findings concerning permanence risks to forest carbon projects. ...
Risks to mitigation potential of forests
Much recent attention has focused on the potential of trees and forests to mitigate ongoing climate change by acting as sinks for carbon. Anderegg et al. review the growing evidence that forests' climate mitigation potential is increasingly at risk from a range of adversities that limit forest growth and health. These include physical factors such as drought and fire and biotic factors, including the depredations of insect herbivores and fungal pathogens. Full assessment and quantification of these risks, which themselves are influenced by climate, is key to achieving science-based policy outcomes for effective land and forest management.
Science , this issue p. eaaz7005
... In a well-regarded proposal, Wilcoxen and McKibbin [2] proposed caps by country with international trading: "Because the total supply of permits in any year would not be fixed, the policy would not guarantee precisely how much abatement will take place in that year." Where ETSs do attempt to reach a particular limit, the limit can be subverted (e.g., California; [3]), 1 3 is bottom-up incentives for joining, and these incentives increase over time under plausible conditions, potentially resulting in a broad rush to join while inhibiting dropouts. Section 2 describes the centralized auction. ...
In this paper, I introduce a new emissions trading system (ETS) design to address the problems with existing ETSs and carbon taxes. First, existing ETS designs inhibit emissions but do not constrain warming to any set level. Existing ETSs have the indirect objective of reducing emissions instead of directly reducing warming. Even a global mechanism using an existing ETS cannot guarantee a particular warming path. Part 1: A Price on Warming addresses this. My proposed market trades contracts tied to temperature in a double-sided auction of emissions permits and sequestration contracts. Unlike existing ETSs, the mechanism has a consistent timescale and metric tied to warming, with explicit limits on global temperature in every period into the far future. Every auction finds prices for emissions into the far future. Second, if a jurisdiction does not require firms to manage their emissions, the firms have little incentive to do so. Part 2: A Climate Insidium addresses this. My design incentivizes firms to participate even if their jurisdictions do not join. With sanctions from member jurisdictions and participating firms, the design has bottom-up incentives for joining, and the incentives rise over time under realistic conditions, potentially resulting in a rush to join. Third, existing designs have high transaction costs for implementation, requiring international treaties to begin. Part 3: A Faster Path Forward addresses this. I propose a path without national or international action to begin. A coalition can implement these rules, creating political force to accelerate participation. Full implementation still requires national agreements. This design appears to be closer to "first best", with a lower cost of climate mitigation, than any in the literature, while increasing the certainty of avoiding catastrophic global warming. It might also provide a faster pathway to implementation.
This study aims to estimate the adoption rate of genetically advanced loblolly pine (Pinus taeda) seedlings and
better understand the factors influencing seedling choice among family forest landowners and consulting foresters
in Georgia, a major forestry state in the Southern United States. We conducted two online surveys, one for
landowners and one for registered foresters in Georgia. Our findings reveal that the adoption rate, self-reported
knowledge, and positive perceptions of genetically advanced loblolly pine seedlings were high among respondents
of both surveys. The adoption rate was 13.5 % of all managed forestlands by foresters (29.3 % for
managed loblolly pine stands) and 18.0 % of all the forestlands (37.4 % of managed loblolly pine stands) owned
by family forest landowners. Reasons for adopting among both groups included fast growth and favorable
financial outcomes. However, barriers to adoption include cost, beliefs that other factors are equally or more
important than the genetics of seedlings, and the need for more evidence. Furthermore, a high proportion of each
group expressed an interest in adopting genetically advanced seedlings for increasing carbon revenue over time.
Our findings suggest that more research about the related benefits is needed to increase the adoption of
genetically advanced loblolly pine seedlings. We also found that communicating these benefits using trusted
sources is also necessary. Our study will feed into the growing movement for using better genetics to improve
forest productivity and reduce forest health issues in Georgia and beyond, especially on family forestlands, as
they supply the majority of roundwood and other forest-based ecosystem services.
Estimates reveal a consistent failure to fulfill climate finance targets, with adaptation finance receiving proportionately less than finance directed to mitigating climate breakdown. Financing for loss and damage is even more critically inadequate. Though likely an underestimate, official figures peg adaptation costs at approximately 140–300 billion by 2030 and $280–500 billion by 2050. Much of the scholarly literature and policy work is thus focused on determining how sufficient funds to finance adaptation will be raised and from where they will come. This challenge is perceived as especially acute given the absence of incentives for private sector investment in adaptation projects. The purpose of this chapter is to offer a critical intervention into discussions and debates on the related themes of adaptation finance and adaptation to climate breakdown with a particular focus on carbon markets. Abundant and well-documented evidence shows that carbon offsetting under the Kyoto Protocol allowed polluters in the Global North to avoid taking action, shifting the burden of responsibility for lowering emissions to distant nations and communities; that an overwhelming share of offset projects failed to fulfill their emission reduction commitments resulting in an overall increase in global emissions and that carbon offsetting today represents a dangerous obstacle to achieving real and lasting emission reductions consistent with limiting heating to 1.5°C above pre-industrial levels. This chapter offers an intervention into critically oriented research on adaptation to climate breakdown in the Global South. Much of this literature has documented the problems with adaptation interventions—that they fail to problematize how pre-existing inequalities at the community level shape outcomes and heighten marginalization; that they fail to interrogate multi-scalar sources and structures of vulnerability and oppression, including relations of production and social reproduction, class, gender, race, and more, thereby threatening to reproduce them; that they fail to offer spaces for democratic dialogue, mutual learning and participatory practice in adaptation projects and that they conceptualize adaptation as a technical fix in response to external climate threats, thereby mystifying the imperative to understand climate breakdown and the need for adaptation as deeply enmeshed in, and constituted through, globalized socio-economic and political structures to which we must respond as part of adaptation interventions.
Forest carbon sequestration is a widely accepted natural climate solution, however, methods to determine net carbon offsets are limited to commercial carbon proxies and CO2 eddy covariance research. Non-CO2 greenhouse gases (GHG) (e.g., CH4, N2O) receive less attention in the context of forests, in part, due to emphasis on CO2 and the operational requirements and cost for three-gas eddy covariance platforms. In this study, Howland forest flux tower (CO2, CH4) and soil flux data (CO2, CH4, N2O), representing net emission reductions, are linked to their respective social costs to estimate commercial revenue if sold as a GHG social cost forest offset product (GHG-SCF). Estimated annual revenue for GHG-SCF products, applicable to realization of a Green New Deal, range from ~12,000,000 for extrapolation to 40,000 acres in 2040, assuming a 3% discount rate. The Howland Forest CO2 flux record for two adjacent towers is compared to California Air Resources Board forest carbon proxy data for compliance sequestration offsets, the only project site where these approaches overlap. Overcrediting, incomplete carbon accounting with annual errors of up to 2,256%, inadequate third-party verification, and limited application to non-CO2 GHG’s are established. In contrast, direct measurement of one or more GHG’s offers new forest products and revenue incentives to restore and conserve forests worldwide.
Existing emissions trading system (ETS) designs inhibit emissions but do not constrain warming to any fixed level, preventing certainty of the global path of warming. Instead, they have the indirect objective of reducing emissions. They provide poor future price information. And they have high transaction costs for implementation, requiring treaties and laws. To address these shortcomings, this paper proposes a novel double-sided auction mechanism of emissions permits and sequestration contracts tied to temperature. This mechanism constrains warming for many (e.g., 150) years into the future and every auction would provide price information for this time range. In addition, this paper proposes a set of market rules and a bottom-up implementation path. A coalition of businesses begin implementation with jurisdictions joining as they are ready. The combination of the selected market rules and the proposed implementation path appear to incentivize participation. This design appears to be closer to “first best” with a lower cost of mitigation than any in the literature, while increasing the certainty of avoiding catastrophic warming. This design should also have a faster pathway to implementation. A numerical simulation shows surprising results, e.g., that static prices are wrong, prices should evolve over time in a way that contradicts other recent proposals, and “global warming potential” as used in existing ETSs are generally erroneous.
Forest carbon sequestration offsets are methodologically uncertain, comprise a minor component of carbon markets and do not effectively slow deforestation. The objective of this study is to describe a commercial scale in situ measurement approach for determination of net forest carbon sequestration projects, the Direct Measurement Forest Carbon Protocol™, to address forest carbon market uncertainties. In contrast to protocols that rely on limited forest mensuration, growth simulation and exclusion of CO 2 data, the Direct Measurement Forest Carbon Protocol™ is based on standardized methods for direct determination of net ecosystem exchange (NEE) of CO 2 employing eddy covariance, a meteorological approach integrating forest carbon fluxes. NEE is used here as the basis for quantifying the first of its kind carbon financial products. The DMFCP differentiates physical, project and financial carbon within a System-of-Systems™ (SoS) network architecture. SoS sensor nodes, the Global Monitoring Platform™ (GMP), housing analyzers for CO 2 isotopologues (e.g., ¹² CO 2,¹³ CO 2 , ¹⁴ CO 2 ) and greenhouse gases are deployed across the project landscape. The SoS standardizes and automates GMP measurement, uncertainty and reporting functions creating diverse forest carbon portfolios while reducing cost and investment risk in alignment with modern portfolio theory. To illustrate SoS field deployment and operation, published annual NEE data for a tropical (Ankasa Park, Ghana, Africa) and a deciduous forest (Harvard Forest, Petersham, MA, USA) are used to forecast carbon revenue. Carbon pricing scenarios are combined with historical in situ NEE annual time-series to extrapolate pre-tax revenue for each project applied to 100,000 acres (40,469 hectares) of surrounding land. Based on carbon pricing of 36 per ton CO 2 equivalent (tCO 2 eq) and observed NEE sequestration rates of 0.48 to 15.60 tCO 2 eq acre ⁻¹ yr ⁻¹ , pre-tax cash flows ranging from 16,380,000 across project time-series are calculated, up to 5× revenue for contemporary voluntary offsets, demonstrating new economic incentives to reverse deforestation. The SoS concept of operation and architecture, with engineering development, can be extended to diverse gas species across terrestrial, aquatic and oceanic ecosystems, harmonizing voluntary and compliance market products worldwide to assist in the management of global warming. The Direct Measurement Forest Carbon Protocol reduces risk of invalidation intrinsic to estimation-based protocols such as the Climate Action Reserve and the Clean Development Mechanism that do not observe molecular CO 2 to calibrate financial products. Multinational policy applications such as the Paris Agreement and the United Nations Reducing Emissions from Deforestation and Degradation, constrained by Kyoto Protocol era processes, will benefit from NEE measurement avoiding unsupported claims of emission reduction, fraud, and forest conservation policy failure.
Forest ecosystems are removing significant amounts of carbon from the atmosphere. Both abiotic resource availability and biotic interactions during forest succession affect C accumulation rates and maximum C stocks. However, the timing and controls on the peak and decline in C accumulation rates as stands age, trees increase in size, and canopy gaps become prevalent are not well-understood. Our study
examines measured change in live and dead woody C pools from 8767 inventory plots on 9.1 million ha of Pacific Northwest National Forest lands to determine how the balance of tree growth, mortality, and dead wood decomposition varied by stand age, plant community type, and site productivity; and to compare the contribution of different tree sizes to C accumulation. Maximum non-mineral soil C for old-growth
stands varied significantly by productivity class within plant community types, but on average stands accumulated 75% of maximum stocks by age 127 ± 35 yr. We did not see a decline in net primary production
of wood (NPPw) with age in moderate and low-productivity classes, but found a 33% reduction in
high-productivity classes. Mortality increased with stand age such that net change in live tree biomass, and change in total woody C, was not significantly different from zero in old-growth stands over age 400 (0.15 ± 0.64 Mg C·ha−1·yr−1 for woody C). However, significant though modest C accumulation was found in forests 200–400 yr old (0.34–0.70 Mg C·ha−1·yr−1, depending on age class). Mortality of trees >100 cm diameter exceeded or equaled NPPw, but trees were growing into the larger sizes at a high-enough rate that
a net increase in large tree C was seen across the region. Although large trees accumulated C at a faster rate than small trees on an individual basis, their contribution to C accumulation rates was smaller on an area basis, and their importance relative to small trees declined in older stands compared to younger stands. In contrast to recent syntheses, our results suggest that old-growth and large trees are important C stocks, but they play a minor role in additional C accumulation.
Forest conservation in one country can influence the degree of conservation or deforestation in other countries because of international linkages of the forest products industry and markets and a lack of global coordination. Thus leakage and offsetting losses of environmental quality may be present. This paper develops an analytical framework for measuring this leakage and estimates its magnitude via general equilibrium modeling. We find that the magnitude of leakage depends upon the price elasticities of supply of and demand for forestry products across the countries and degree of cooperation in forest conservation. We estimate that a significant portion (42%–95%) of the reduced forestry production implemented in a country/region can be transferred to elsewhere, offsetting environmental gains. Leakage generally diminishes as more countries cooperate, but cooperation among only a few countries does not always dramatically reduce leakage. Thus forest conservation efforts and associated environmental quantity gains in a country or group of countries can be seriously undermined in terms of global net conservation gain in the absence of effective global cooperation. Our results also point to the importance of taking leakage into account in evaluating local or regional forest carbon sequestration projects.