UNFCCC Posts fNRB Update Research for Public Comment
Research commissioned by UNFCCC to update fraction of non-renewable biomass values has now been posted on their website, launching a three-week public comment period ending November 3, 2023.
The United Nations Framework Convention on Climate Change (UNFCCC) has supported research to establish updated fraction of non-renewable biomass (fNRB) values and released the results for public comment. These results, which include national and subnational values for sub-Saharan Africa (SSA), are derived from recent research conducted by leading scientists at the Stockholm Environment Institute (SEI) and the National Autonomous University of Mexico (UNAM) and are intended to replace previously-used defaults and methodologies. This new data provides an opportunity for harmonization and more accurate accounting of the climate impacts of clean cooking projects.
What is fNRB and how does it relate to cookstove carbon projects?
fNRB is a critical input for calculating emissions reductions from clean cooking interventions. The fraction of non-renewable biomass (fNRB) measures the relative amount of wood that is harvested beyond the landscape’s natural rate of regeneration. When wood is harvested at or below the rate at which it naturally regenerates, then the cutting of trees, limbs, and other wood is considered sustainable. However, if more wood is harvested than the landscape can replace, as is often the case in low- and middle-income countries where households and communities rely heavily on fuelwood and charcoal, then harvesting is not sustainable, and tree cover will decline over time. This leads to landscape degradation and may also contribute to long-term deforestation.
When households transition to more efficient cooking practices, forest degradation—as well as climate-warming emissions—are reduced, because trees remain standing, and any carbon that would have been emitted as CO2 when burned remains sequestered in those trees. These reduced emissions generate carbon credits for cooking projects. Locations with higher fNRB values (meaning larger percentages of wood harvest are non-renewable) have the potential for greater emissions reductions.
[ Learn about the impacts of clean cooking on the climate and environment. ]
How have fNRB calculations changed over time?
fNRB has been integral to carbon methodologies for clean cooking since the first projects were developed in the late 2000s. Its purpose is to allow project developers to account for the fact that some of the trees that are cut for fuel will regenerate; not all avoided forest harvesting results in reduced carbon emissions.
However, early methodologies relied on imperfect approaches to determine fNRB, which in many cases produced overestimates of the mitigation potential of certain projects.1 For example, some methodologies assumed that renewable biomass originated only from land under formal management or set aside for conservation purposes and that biomass coming from other regions was non-renewable, when in fact renewable and non-renewable conditions can exist in many contexts. Some methodologies that did recognize this distinction offered insufficient guidance on the kind of sources that could accurately determine annual woody biomass regeneration in a given area, or on how to design field surveys to accurately determine biomass regeneration rates.
Over time, UNFCCC and voluntary carbon standards bodies modified their methodologies to improve on earlier approaches. These improvements culminated in “TOOL30 Calculation of the fraction of non-renewable biomass,”2 which was first released in 2017 and has been refined several times since. However, when TOOL30 was released in Nov 2017, default fNRB values ranging from 80% to 90% were still in effect.3 This implies that wood was being harvested in those countries at 5-10 times the rate at which forests and woodlands regenerate nationwide.
In 2015, the Clean Cooking Alliance funded a more detailed assessment of fNRB across 90 low- and middle-income countries located mostly in tropical regions and found numbers that were lower than the initial CDM defaults. The resulting paper (Bailis et al. 2015) was the basis for a 30% global default value offered as one option for the fNRB parameter in the latest version of TOOL30.4 Alternatively, project developers could also independently calculate fNRB following an earlier methodology but with more robust guidance for selecting tool inputs as well as specific, reliable data sources. However, these calculations can vary significantly depending on multiple input factors. For example, selecting whether trees grow at the pace of recently disturbed “secondary” forest or a primary “old-growth” forest can result in measurably different fNRB values.
In the last year, the gap between the global default value of 30% and the fNRB values of up to 80-90% generated by the CDM tool and used by many clean cooking projects has received significant attention. This gap has raised concerns about integrity and possible over-crediting in cookstove projects.
Why did UNFCCC commission research on fNRB values now?
Integrity of emissions reductions is paramount to a functioning carbon market, and, for clean cooking, fNRB is currently a key input to accurate estimations. Given the wide variability in estimates that can be generated by TOOL30, and the lack of ability to target areas of high non-renewability when using a global average of 30% across the board, there is a need for new data that can create full confidence among companies and governments purchasing carbon offsets, while allowing for important geographic contextualization. Further, the latest data on fNRB were from 2009, so the CDM Executive Board requested that the Methodologies Panel review more recent data to develop subnational/regional values of fNRB, building on scientific studies and engaging external experts.
What does the new fNRB research tell us?
The new assessment uses the peer-reviewed MoFuSS model, also developed by scientists from UNAM and SEI.5 MoFuSS runs simulations of wood supply and demand, which allows users to compare intervention and non-intervention scenarios while accounting for variables like population growth, urbanization, and land cover change. MoFuSS is built with freely available software with open-source code, making it transparent and accessible. It is a bottom-up spatial model that can be aggregated to any level, allowing for fNRB estimates to be made for any administrative unit (e.g., districts, counties, states, provinces, etc.) as well as customized regions that cut across administrative boundaries. The UNFCCC-commissioned model relies on harmonized global datasets that are regularly updated, which facilitates periodic updates to fNRB estimates.
Results from this research indicate that while fNRB values for Sub-Saharan Africa vary widely, in most cases country-level fNRB values are higher than the previous global default of 30% but lower than those values generated using CDM TOOL30.
What are the next steps for the new fNRB research?
The UNFCCC’s CDM Methodologies Panel has reviewed, provided feedback to and posted a summary of the current fNRB research on their website, launching a three-week public commenting period on the approach adopted and proposal for improvement. The Panel has simultaneously referred the research to the CDM Executive Board (EB) for review, recommending that the Board take note of the information and provide further guidance. The information is included in the meeting report of the CDM Methodologies Panel in paragraph 34 here, and Annex 7 “Information note on default values for fNRB” here.
At their next meeting in late November, the EB will consider the public comments as well as the information provided by the Methodologies Panel. While the EB has the authority to approve the new values for SSA at their November meeting, given the potential impact of these changes on the sector and the fact that the Methodologies Panel will continue to work on this based on public comments, the EB will likely defer the decision to 2024.
If and when the Executive Board approves the new values, Gold Standard and Verra will likely start using the new values immediately for new projects going forward. Because the registration of new projects are no longer possible under the CDM, the use of the new fNRB values in the compliance market will depend on how they are integrated into the transition from the CDM to Article 6.4. Retroactive changes in fNRB values for previously registered projects are not planned for either the compliance market or the voluntary market, so as to not undermine contractual obligations established around prior values.
Given these new fNRB values, are carbon credits using the old values still credit-worthy?
As the clean cooking sector is dedicated to continuous improvement, it must recognize that frequently recalibrating to align with the best and most recent science will mean that approaches and inputs, including default values, will change over time. For the market to function, contractual obligations based on prior best-available data must be honored even as data evolve. The overwhelming majority of previous fNRB analyses applying TOOL30 represented good faith attempts to estimate fNRB values, often using the most recently available peer-reviewed, authoritative data on forest cover and biomass consumption rates. The resulting carbon credits are still credit-worthy.
What else is going on in the clean cooking ecosystem related to this research?
These updated fNRB values are part of UNFCCC’s continual efforts to ensure that clean cooking projects are grounded in sound methodologies and the most up-to-date, reliable data. These improvements are broadly supported by the clean cooking sector, which strives to continually improve the quality of carbon projects as new research becomes available. The introduction of the Article 6 mechanism in particular has led to a reassessment of approaches to emission reduction accounting across all sectors, including clean cooking. The Clean Cooking and Climate Consortium (4C) is in the process of developing a new methodology for crediting emissions reductions from cooking projects, in close collaboration with UNFCCC, voluntary standards bodies, project developers, and other key stakeholders across the ecosystem. This new methodology will refer to these new fNRB values, and as part of this work, 4C is coordinating with standards bodies to ensure aligned use of fNRB values, among other parameters, to create consistency and transparency for the sector. These efforts will be complemented by a centralized, free online platform—being developed by CCA and SEI—that will lower barriers to entry for project developers by aggregating key input data for clean cooking carbon projects, including national and subnational fNRB values.
What are the opportunities for the clean cooking ecosystem going forward?
The new, more robust fNRB values will result in fewer credits issued for many cookstove carbon projects going forward. However, buyers need confidence that credits are grounded in the latest science, and as a sector, clean cooking is leading the path to increased transparency and integrity within the carbon market.
The revision of fNRB values, grounded in improved data, provides an opportunity for harmonization across the clean cooking carbon ecosystem and allows for more granular and accurate accounting of the climate impacts of clean cooking projects. This will enable stakeholders to more accurately identify geographic areas where clean cooking projects will deliver the largest climate benefits and will allow project developers to utilize fNRB values that are more representative of the geographic region in which a project takes place, depending on national regulations. In the long term, this consistency, improved data and greater integrity should lead to greater investment in clean cooking carbon by attracting new buyers and supporting favorable project terms, allowing projects to remain viable and resulting in more reliable carbon funding flows for the vital climate and development solution of clean cooking.
1 Bailis, Robert, Yiting Wang, Rudi Drigo, Adrian Ghilardi, and Omar Masera. “Getting the Numbers Right: Revisiting Woodfuel Sustainability in the Developing World.” Environmental Research Letters 12, no. 11 (2017): 115002. https://iopscience.iop.org/article/10.1088/1748-9326/aa83ed
2 See https://cdm.unfccc.int/methodologies/PAmethodologies/tools/am-tool-30-v1.pdf/history_view. The most recent versions of Gold Standard’s clean cooking methodologies also recommend using TOOL30 (see for example, https://globalgoals.goldstandard.org/407-ee-ics-technologies-and-practices-to-displace-decentrilized-thermal-energy-tpddtec-consumption/)
3 https://cdm.unfccc.int/DNA/fNRB/index.html
4 Bailis, Robert, Rudi Drigo, Adrian Ghilardi, and Omar Masera. “The Carbon Footprint of Traditional Woodfuels.” Nature Climate Change 5 (2015): 266–72. https://doi.org/10.1038/nclimate2491
5 Ghilardi, Adrián, Robert Bailis, Jean-François Mas, et al. “Spatiotemporal Modeling of Fuelwood Environmental Impacts: Towards Improved Accounting for Non-Renewable Biomass.” Environmental Modelling & Software 82 (August 1, 2016): 241–54. https://doi.org/10.1016/j.envsoft.2016.04.023
