Forest Methane Questions

Do trees absorb methane?

Living trees take up methane through their bark. Bacteria in the bark, called methanotrophs, oxidize methane directly from the air. Our 2024 study in Nature measured this across upland forests worldwide and estimated a global uptake of 24.6 to 49.9 million tonnes of methane a year, strongest in tropical forests.

How does methane uptake in bark work?

Methanotroph bacteria living in the bark consume methane at the low concentration found in ordinary air, about 2 parts per million. They oxidize it to CO₂ and water and use the energy released. A forest has a very large woody surface area, so this uptake per unit area adds up to a sink across the whole forest.

How much methane does a forest absorb?

The 2024 Nature study estimated a global sink of 24.6 to 49.9 million tonnes of methane a year. Woody surfaces worldwide total about 143 million square kilometres, close to the area of Earth's land, so a small uptake per unit area sums to a large global figure. For a tropical forest at the upper end of the range, uptake is about 16.8 kg of methane per hectare per year.

Is bark methane uptake the same as soil methane uptake?

Bark methane uptake is a separate sink from soil methane uptake. Soils have long been known to take up methane through methanotrophs, removing on the order of 30 million tonnes a year. Our 2024 Nature study found that tree bark adds a sink of the same order of magnitude, one that national greenhouse-gas inventories had not counted.

Is the science peer-reviewed?

Our central measurement was 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 traps much more heat than CO₂. It also lasts far less time in the air, roughly a decade. Over 100 years its warming is about 27 times that of CO₂ for biogenic methane (IPCC AR6). Because it is short-lived, removing methane now reduces near-term warming relatively quickly.

How does SelvaFlux measure methane uptake?

SelvaFlux measures the flux directly on the tree. A chamber and a laser gas analyzer sit against the bark and record how fast methane is drawn down, sampled up the stem and across species. Terrestrial laser scanning then measures the woody surface area of the forest, and the per-area flux is scaled to the whole site. Satellite data maps uptake across the landscape, calibrated against the 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. Combining surface area with measured flux produces a site-level uptake estimate that 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 produces a per-site estimate from field flux and measured surface area. Under an approved method, an accredited verifier would review the estimate before a registry issued credits.

Is bark methane uptake a carbon offset?

For a forest carbon project, bark methane uptake could become a carbon credit through a module added to an approved forest methodology. A national greenhouse-gas inventory would report the same uptake as part of the methane balance. Inventory reporting does not create a credit, an offset, or a licence to emit.

Can you buy or sell this credit today?

Bark methane credits cannot be bought or sold today. We estimate that crediting is one to two years away. The crediting module is in concept consideration at Gold Standard (registry ID NMC 187), and a parallel module at Verra (Development ID M0423) is on hold pending Verra's reassessment in Q1 2027. The measurement method is patent pending and the mapping tool is built. Pilots are underway across the tropics.

Does SelvaFlux verify its own credits?

SelvaFlux does not verify its own credits. SelvaFlux measures the uptake and builds the methodology. Registries require independent, third-party verifiers, and an accredited verifier checks the work before the registry issues any credit.

Does the methane credit meet the same standards as other carbon credits?

An approved methane credit would be subject to the host project's baseline and additionality rules and to the methane method's own 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. Measuring the flux precisely does not correct a weak host-project baseline.

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 require evidence that the net uptake is attributable to an eligible forest project relative to 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 claimant would need to hold the legal and contractual right to the methane attribute. Project agreements, carbon-rights records, registry records, and earlier sales would need to show that the uptake had not been assigned or counted elsewhere. National inventory reporting records the physical uptake and does 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 a fully financed existing project, 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 prospective methane revenue changes modeled bankability and peak funding need. A separate completion scenario applies an assumed response that has not been fitted to observed project data. 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 a fully financed existing project, the purchase did not cause past planting. A payment made before financial close, during incomplete planting, or before a defined expansion can affect a current decision. A restoration or project-delivery claim requires records made at the time showing the financing gap, use of proceeds, affected area, and the decision 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.

How much revenue does bark methane add to a forest project?

In the spatial model, prospective methane revenue raises the area-weighted present value of credit revenue by 2.9% under GWP100 and 10.8% in the separate GWP* scenario. The result varies among grid cells because forest growth, temperature, land income, and assigned project costs vary. No registry currently credits bark methane.

How does methane revenue change bankability?

The spatial model calculates a separate break-even price for each tropical grid cell. At $50 per tonne, 32.0 million hectares are bankable with biomass carbon revenue alone. Prospective methane revenue increases that area to 33.7 million hectares under GWP100 and 38.5 million hectares in the GWP* scenario. 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 supply-curve results using assumed distributions of carbon purchase prices. Prospective methane revenue adds 0.8 to 1.7 million hectares of bankable land under GWP100 and 3.1 to 6.3 million hectares in the GWP* scenario. These ranges depend on the price assumptions. Observed purchase volumes were not used.

Does methane revenue reduce the funding a project needs?

In the spatial cash-flow model, peak funding need falls by 1.3% under GWP100 and 4.5% in the GWP* scenario. The model assumes methane-credit payments arrive after a one-year lag. It does not estimate advance-purchase funding before planting.

What does the completion scenario estimate?

The completion scenario applies an assumed response to land that is already bankable. It estimates an increase in completed area of 0.3 to 0.5 million hectares under GWP100 and 1.2 to 1.9 million hectares in the GWP* scenario. The response has not been fitted to observed project data. We report it separately and do not publish a combined delivery result.

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 biomass-growth inputs. The bankability and funding results come from a spatial cash-flow model across tropical grid cells. The completion figures come from a separate scenario that has not been fitted to observed project data.

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 reports GWP* as a scenario for 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. Registries do not currently credit bark methane or use GWP* as the crediting basis.

GWP100, GWP20, or GWP*: which one applies here?

GWP100 is the metric registries currently apply to approved methane credits and values biogenic methane at about 27 times CO₂ over 100 years. GWP20 describes warming over a 20-year window. GWP* describes the warming-equivalent effect of a sustained change in the methane removal rate. SelvaFlux reports GWP100 as the current-metric case and labels GWP* as a separate new-sink scenario. Under this calculation, measurement that begins after sink formation does not create a new flux change at the measurement date.

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 a forest by its carbon and methane, which is a human-use framing, and 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 piloting across the tropics, where bark methane uptake is strongest and where reforestation and forest-carbon projects are concentrated.

Who is SelvaFlux for?

Forest carbon project developers and owners, who gain a new revenue line; carbon buyers, who gain a new credit type; impact investors; and governments measuring national methane sinks.

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.