Forest methane and carbon credits
Forest Methane Questions
These answers explain forest methane uptake, measurement, company accounting and potential credits. They link to the science, current rules and project economics.
Update, 19 September 2026: this July video describes our earlier metric policy. SelvaFlux now uses GWP20 for its main methane calculations. We also report GWP100 results and calculate potential GWP* payments if buyers and registries accept them. The video simplifies the uptake process. Researchers are still studying where in trees the organisms that consume atmospheric methane live. Read the GWP20 explanation and sources.
The science
Methane Uptake by Forests
Do trees absorb methane?
Living trees take up methane through their woody surfaces. Our 2024 Nature study measured uptake at four upland forest sites and found evidence consistent with microbes consuming the methane. Researchers are still studying where these organisms live within the tree. Scaling these measurements to the world's forests gave an estimated uptake of 24.6 to 49.9 million tonnes of methane a year, with the highest rates in tropical forests.
How does methane uptake in bark work?
The woody surfaces of trees take up methane at the low concentration found in ordinary air, about 2 parts per million. The findings are consistent with microbes consuming it. Methane-oxidizing bacteria commonly use oxygen and release CO₂ and water. Researchers are still studying where these organisms live within the tree and how they process methane. Each small area of bark takes up a little methane. Across a forest's large woody surface area, that uptake adds up.
How much methane does a forest absorb?
Our 2024 Nature study estimated that woody surfaces take up 24.6 to 49.9 million tonnes of methane a year worldwide. These surfaces total about 143 million square kilometres, close to the area of Earth's land. A small uptake per unit area therefore adds up to a large global total. Our model uses 16.8 kg of methane per hectare per year as its reference rate for warm tropical forests.
Is bark methane uptake the same as soil methane uptake?
Bark and soil each take up methane. Scientists have long known that microbes in soils remove about 30 million tonnes a year. Our 2024 Nature study found that tree bark removes a broadly similar amount. National greenhouse gas inventories had not counted this bark uptake.
Is the science peer-reviewed?
Our methane uptake measurements were peer reviewed and published in Nature in 2024. Independent studies from other research groups also report methane oxidation in bark and stems.
How harmful is methane compared with CO₂?
Methane remains in the atmosphere for about a decade and causes strong near-term warming. IPCC AR6 Table 7.SM.7 gives a GWP20 of 81.2 and a GWP100 of 27.9, excluding methane-carbon accounting. These compare the heat-trapping effect of a methane pulse with the same mass of CO₂ over 20 and 100 years. Our model keeps its earlier factor of 27, the non-fossil GWP100 value in AR6 Table 7.15, which treats methane-derived carbon differently. Removing methane can reduce warming over the following decades.
Measurement
How We Measure Methane Uptake
How does SelvaFlux measure methane uptake?
SelvaFlux measures methane uptake directly on the tree. We place a chamber against the bark and use a laser gas analyzer to measure how quickly the methane concentration falls. We repeat the measurements at different heights on the stem and across species. Terrestrial laser scanning measures the forest's woody surface area. We combine that area with the measured uptake rate to estimate uptake across the site. SelvaFlux has also built a satellite mapping tool. Pilots will calibrate and test its estimates against field measurements.
What is terrestrial laser scanning?
Terrestrial laser scanning uses a ground-based laser to build a detailed 3D model of trees and forest structure. SelvaFlux uses it to measure woody surface area, the surface across which bark takes up methane. We combine the surface area with the measured uptake rate to estimate uptake across the site. That estimate could support a claim under an approved method.
Can it be measured accurately enough to credit?
Crediting requires an uptake figure that an independent auditor can check. SelvaFlux estimates uptake for each site from field measurements of uptake rates and woody surface area. Under an approved method, an accredited verifier would review the estimate before a registry issued credits.
Credits and status
Credits, Methodology, and Status
Is bark methane uptake a carbon offset?
Bark methane uptake could support a carbon credit if a registry approves an applicable method and issues units after project verification. A buyer's ability to use those units as offsets would depend on the rules for that claim. The current Verra and Gold Standard bark proposals have not been approved. National inventory reporting is a separate process and does not issue project credits.
Can you buy or sell this credit today?
Bark methane credits cannot be bought or sold today because no registry credits bark methane. Gold Standard is considering the concept under NMC 187. Verra's parallel module, M0423, is on hold. Verra plans to decide in the first quarter of 2027 whether to restart development. That decision would not approve the module. SelvaFlux plans for a first issued credit in 2030 or later. Approval is not guaranteed, and registry timelines can slip. The measurement method is patent pending and the mapping tool is built. No pilot agreement has been signed. SelvaFlux is discussing candidate sites with developers and preparing the field measurement system and pilot terms.
Does SelvaFlux verify its own credits?
Any future bark methane credits would require independent verification. SelvaFlux measures uptake and is developing the methodology. Under an approved method, an accredited third-party verifier would check the work before a registry decided whether to issue credits.
Does the methane credit meet the same standards as other carbon credits?
An approved methane credit would have to meet the forest project's baseline and additionality rules, as well as the methane method's eligibility and accounting rules. The methane method would need to address the methane baseline, uncertainty, leakage, permanence, reversals, and overlapping claims.
Bark methane uptake lasts only while the forest stands, so loss of the forest would stop the sink. Accurate uptake measurements cannot correct an unreliable estimate of what would happen without the forest project.
If trees already absorb methane, how could methane credits be additional?
Measurement alone does not make methane uptake additional or eligible for crediting. A credit claim would need evidence that an eligible forest project caused the net uptake above an approved baseline. Uptake expected without the project belongs in the baseline.
For reforestation, the methane claim would cover uptake associated with forest created by the project relative to the land-use baseline. For forest protection, it would cover uptake preserved relative to a credible baseline of expected forest loss. The eventual methane method must define these calculations.
An approved method would need to set the eligibility rules for existing projects. It would need to define how the host project's baseline and additionality finding apply to the methane claim, along with eligible project types, start dates, monitoring periods, crediting periods, and the treatment of measurements collected before approval. No registry has approved these rules for bark methane. Existing projects would need to be assessed under the approved rules.
The person or organization claiming the methane uptake would need the legal and contractual right to do so. Project agreements, carbon-rights records, registry records, and earlier sales would need to show that the uptake had not been assigned or counted elsewhere. A national inventory document could describe the physical uptake and state that the inventory does not yet estimate it. The document could also identify a method the country plans to develop. That description would not create another credit. The methane method would still need to define how project claims interact with national reporting and other claims. The calculation would need to apply uncertainty, leakage, permanence, and reversal rules and receive independent verification before registry issuance.
For an existing project that already had full funding, later methane revenue did not cause the original planting or protection decision. The project could still produce eligible methane units if the uptake is attributable under the approved rules. A claim that a methane purchase caused more restoration would require records showing that the payment changed financing, remaining planting, continued maintenance, a defined expansion, or a later project.
The wider market effect is separate. The spatial model estimates how methane payments could change the area where projects meet their required return and the funding they need. A separate calculation tests several possible relationships between project returns and the area of forest completed. We do not yet have enough reforestation project records to measure that relationship directly. These results do not show that a particular purchase caused a particular hectare. SelvaFlux does not combine modeled hectares with measured methane uptake as one impact total.
Does this double-count the forest's carbon?
Under an approved method, methane uptake would be quantified separately from a project's biomass carbon. SelvaFlux would report each quantity separately. The methane method must also prevent overlap with any methane effect already included in the host project's accounting.
Does a project have to change how it manages the forest?
Measuring bark methane does not require a separate change to forest management. Future credit eligibility would still depend on the host project's baseline and additionality and on the requirements of an approved methane method.
Would buying methane credits cause more restoration?
Buying methane credits does not by itself show that the buyer caused more restoration. For an existing project that already had full funding, the purchase did not cause past planting. A payment can affect a decision if it arrives before financing is agreed, while planting is incomplete, or before a defined expansion. To claim that a purchase caused more restoration or helped complete a project, a buyer needs records made at the time. Those records must show the funding gap, how the money was used, the affected area, and what decision was expected without the payment. The spatial model estimates a possible wider response under stated assumptions. It does not establish the effect of a specific purchase.
Accounting rules
Company Funding and Methane Accounting
Accounting answers reviewed . See upcoming rule changes.
Could a company fund a bark methane pilot through SBTi's contribution framework?
The Science Based Targets initiative (SBTi) provides for research and advance funding through Ongoing Emissions Responsibility (OER). Bark methane pilots could fit these categories if they meet the program's requirements. The Corporate Net-Zero Standard version 2 takes effect on 1 February 2027.
Could verified bark methane uptake count as an SBTi contribution?
Bark methane uptake may fit SBTi's natural-sink category, but its classification needs confirmation. Ongoing Emissions Responsibility (OER) requires quantified outcomes in tonnes of carbon dioxide equivalent (tCO₂e), independent assurance and safeguards against double claiming.
Can bark methane uptake count toward a company's SBTi FLAG target?
SBTi's current Forest, Land and Agriculture (FLAG) rules accept eligible CO₂ removals. Bark methane uptake does not qualify under that rule. Outcomes supported through Ongoing Emissions Responsibility (OER) cannot also meet the company's emissions targets or be deducted from its emissions inventory.
Can a company report bark methane uptake under GHG Protocol?
GHG Protocol's Land Sector and Removals Standard provides for separate reporting of non-CO₂ removals from 1 January 2027. A company would still need an applicable bark methane method and evidence of how the forest relates to its operations or supply chain. Purchased credits remain separate from company emissions totals.
How could bark methane uptake fit into the Paris Agreement?
Countries could account for bark methane uptake in nationally determined contributions (NDCs), their climate plans under Article 4. Article 13 reporting would need a suitable estimation method. Article 5 covers forests and sinks. Article 6 provides for cooperation, including transfers, a UN crediting mechanism and non-market approaches, each with its own requirements.
Reporting uptake in a national inventory does not create a credit. International transfers also need the applicable authorization and accounting, including corresponding adjustments where required to avoid double counting.
Could a buyer pay for tonnes of methane uptake directly?
A buyer could agree to pay for a specified quantity of methane uptake in tonnes of methane (tCH₄). The contract would state the measurement period and what the buyer could claim. A contract using carbon dioxide equivalent (CO₂e) would also state its metric and conversion factor. SelvaFlux uses GWP20 for its main payment calculations, with an assumed price per GWP20 unit. Issuing registry credits would also require a crediting program and an approved method. A direct methane contract does not establish eligibility for SBTi contributions, targets or national accounting. Reporting the same uptake in both tCH₄ and CO₂e does not allow it to be claimed twice.
Economics
Economics for a Forest Project
How much revenue does bark methane add to a forest project?
We calculate revenue for each grid cell across 89.0 million hectares of potential reforestation land. Compared with biomass carbon revenue alone, methane payments increase revenue by an average of 8.7% using GWP20, 2.9% using the model's GWP100 factor, and 10.8% if buyers and registries accept GWP*. Each cell's percentage increase is weighted by its area. We assume the same dollar price per biomass CO₂ unit and per methane unit. The results vary with forest growth, temperature, land income, and assigned project costs. No registry currently credits bark methane.
How much more land could methane payments make financially viable?
The model calculates the price each tropical grid cell needs for a forest project to meet its required return. At an assumed price of $50 per biomass CO₂ unit, 62.5 Mha meet that return with biomass revenue alone. If methane units sell for the same dollar price, the area increases to 67.5 Mha using GWP20, 64.2 Mha using the model's GWP100 factor, and 68.6 Mha if buyers and registries accept GWP*. Each grid cell uses mapped forest growth and net agricultural income, plus an assigned project type and fixed project costs.
What changes when carbon purchase prices vary?
We weighted the model results using assumed patterns of carbon purchase prices. Methane payments make an additional 1.8 to 4.6 million hectares financially viable using GWP20, 0.7 to 1.5 million hectares using the model's GWP100 factor, and 2.2 to 5.7 million hectares if buyers and registries accept GWP*. We assume the same dollar price per biomass CO₂ unit and per methane unit. These ranges depend on the price assumptions. We did not use observed purchase volumes.
Does methane revenue reduce the funding a project needs?
The model calculates each grid cell's largest gap between accumulated spending and revenue over the project's life. It then averages those amounts over the 62.5 Mha already financially viable without methane, giving each cell a weight based on its area. Methane payments reduce this average funding need by 4.3% using GWP20, 1.6% using GWP100, and 5.4% if buyers and registries accept GWP*. The model assumes methane payments arrive one year after uptake occurs. It does not include advance purchases made before planting.
Could methane payments help projects complete more planting?
We tested several assumptions about how higher project returns might increase completed forest area. The calculation covers land that is already financially viable without methane payments. It estimates an additional 1.88 to 2.30 million hectares completed using GWP20, 0.64 to 0.84 million hectares using GWP100, and 2.43 to 2.85 million hectares if buyers and registries accept GWP*. We do not yet have enough reforestation project records to measure how returns affect completion. We report this result separately and do not publish a combined estimate of completed forest area.
Where do these numbers come from?
The uptake figures come from our 2024 Nature study. Published forest-carbon datasets, including Cook-Patton et al. 2020, supply the forest growth estimates. We use a cash-flow model for tropical grid cells to estimate which areas could meet the required return and how much funding they would need. A separate calculation tests several possible relationships between project returns and completed forest area. We do not yet have enough reforestation project records to measure that relationship directly.
Climate metrics
Measuring Methane's Warming
Why does SelvaFlux use GWP20, and how are Google and Terradot using it?
GWP20 compares the heat-trapping effect of a pulse of methane with that of the same mass of CO₂ over 20 years. Our 2024 Nature study measured methane uptake by the woody surfaces of upland trees. We use GWP20 for our main methane comparison and potential payment calculations because it gives more weight to methane's near-term effect. We also report GWP100 results and use GWP* to describe changes through time. Buyers could use GWP* to calculate future payments if they and the relevant registries accept it.
Google has agreed to buy methane reductions from Terradot using GWP20. On 16 September 2026, Google announced a purchase of 1 million tonnes CO₂e (GWP20) of methane elimination by 2030 from changes to rice irrigation in Brazil. The agreement also covers a separate 1 million tonnes of permanent carbon removal by 2040 through enhanced rock weathering. Google links to a research preprint by Hughes and colleagues that models the temperature effect of combining methane mitigation with durable CO₂ removal. The announcement gives no methane price or conversion factor. The agreement does not establish approval of tree methane credits.
SelvaFlux uses 81.2 tonnes CO₂e per tonne CH₄ from IPCC AR6 Table 7.SM.7. That factor excludes methane-carbon accounting. We report tonnes of methane as well as CO₂e. We have not estimated the separate adjustment for carbon derived from methane, so these figures cover the methane component. They do not account for everything needed to calculate net project credits. The model keeps its earlier GWP100 factor of 27, the non-fossil value in AR6 Table 7.15, which treats methane-derived carbon differently. Table 7.SM.7 gives a GWP100 factor of 27.9 alongside 81.2, both excluding methane-carbon accounting. We assume the same dollar price for a biomass CO₂ unit and a methane unit. The higher revenue calculated with GWP20 depends on that price assumption.
Does a new IPCC report change methane accounting rules?
Each accounting body decides which Intergovernmental Panel on Climate Change (IPCC) assessment it uses. GHG Protocol recommends Sixth Assessment Report (AR6) values. The Science Based Targets initiative's Forest, Land and Agriculture (FLAG) rules specify AR6 100-year global warming potential (GWP100). Paris reporting uses Fifth Assessment Report (AR5) GWP100 values until its governing body adopts later values. A new assessment does not automatically change those rules.
What is GWP*, and why does SelvaFlux use it?
GWP* expresses the warming effect of a change in the rate of a short-lived gas such as methane (Allen et al. 2018; Lynch et al. 2020). For reforestation, SelvaFlux uses GWP* to calculate the effect of establishing a new methane sink. The scenario assumes full mature-forest bark uptake from the first modeled year. Uptake development in restored forests has not been measured. Bark methane crediting still requires an approved method. We also calculate potential GWP* payments, assuming buyers and registries accept GWP* from the start of the project.
GWP100, GWP20, or GWP*: which one applies here?
SelvaFlux uses GWP20 at 81.2 tonnes CO₂e per tonne CH₄ for its main methane comparison and potential payment calculations. This factor excludes methane-carbon accounting. For GWP100, the model keeps its earlier factor of 27. We also report 27.9 under the IPCC supplementary table's convention. GWP* depends on how methane uptake changes over time. We use it to calculate the warming effect and potential future payments if buyers and registries accept it. A buyer, registry or reporting program must specify its accepted metric and factor. Beginning measurement after a sink forms does not create a new change in uptake at that date.
Co-benefits and scope
Co-benefits and Scope
What are the co-benefits of keeping forests standing?
When methane revenue helps keep a forest standing, its other functions continue. These include habitat for most land-living species, rainfall for downwind farmland through the forest's moisture recycling, local cooling of about 1°C on average and up to 2.4°C (Lawrence et al. 2022), coastal protection from mangroves, lower malaria risk, and rural livelihoods. These are co-benefits of standing forest. SelvaFlux does not sell them as credits.
Do forests and ecosystems have rights?
A growing legal movement argues they do. The idea, called rights of nature, holds that ecosystems and species have a right to exist on their own terms, regardless of their value to people. It has entered law in several places: Ecuador wrote rights of nature into its 2008 constitution, the first country to do so; New Zealand granted the Whanganui River legal personhood in 2017; and in 2025 the Inter-American Court of Human Rights recognized nature as a subject of rights in an advisory opinion. Scholars disagree on whether these laws change outcomes or stay mostly symbolic. SelvaFlux measures forests' carbon storage and methane uptake for their value to people. It takes no position in this debate.
Aren't forests the lungs of the planet?
A mature forest is roughly oxygen-neutral. Respiration and decomposition consume about as much oxygen as photosynthesis produces. Forest protection matters for carbon storage, biodiversity, water, local climate, livelihoods, and methane uptake.
Where does SelvaFlux operate?
SelvaFlux is discussing tropical candidate sites with developers. No pilot agreement has been signed. SelvaFlux is preparing the field measurement system and pilot terms.
Who is SelvaFlux for?
SelvaFlux is for forest carbon project developers and owners seeking additional revenue, buyers interested in future methane credits, impact investors, and governments measuring national methane sinks.
It is also for companies exploring whether upland forest methane uptake on land they manage or buy products from could count against their methane emissions. Counting this uptake toward Science Based Targets initiative (SBTi) targets would require an accepted method and changes to current rules.
About
About SelvaFlux
Who leads and advises SelvaFlux?
Alexander Shenkin is the founder and CEO. Amy Wolkowinsky coordinates project planning and field-data operations. Greg Ives advises on project finance and carbon markets. Jane Zelikova is an advisor and Executive Director of the Sustainability Research Initiative at the University of Colorado Boulder.
What is SelvaFlux's connection to the Mulago Foundation?
Alexander Shenkin, founder and CEO of SelvaFlux, received the Mulago Foundation's Henry Arnhold Fellowship in 2026.
Who conducted the measurement research?
Our 2024 Nature study measured methane uptake by woody surfaces across upland forests. The team's peer-reviewed work on terrestrial laser scanning and forest structure supports the surface-area estimate used to scale bark flux across a forest.
Talk to the SelvaFlux Team
Pilot partners and buyers can reach us directly. The Science and Impact pages explain the research and calculations and link to their sources.