Forest methane and carbon credits
Questions and Answers
Common questions about forest methane uptake and how SelvaFlux measures and credits it. Each answer links to the pages and peer-reviewed sources behind it.
The science
Forest Methane, the Science
Do trees absorb methane?
Yes. Living trees take up methane through their bark. Bacteria in the bark, called methanotrophs, oxidize methane directly from the air. A 2024 study in Nature (Gauci et al.) 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?
No. It is a separate sink on a different surface. Soils have long been known to take up methane through methanotrophs, removing on the order of 30 million tonnes a year. The 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?
Yes. The central measurement is published in Nature (Gauci et al. 2024), which is peer-reviewed, and SelvaFlux's founder is a co-author. 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.
Measurement
How SelvaFlux Measures It
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 that surface area with the measured flux gives methane uptake for the whole forest, which is the figure a project is credited on.
Can it be measured accurately enough to credit?
Crediting requires an uptake figure that an independent auditor can check. SelvaFlux produces a per-site figure from the field flux and the measured surface area, and independent verifiers check it before any credit is issued.
Credits and status
Credits, Methodology, and Status
Is bark methane uptake a carbon offset?
It depends on the use. For a forest carbon project, bark methane uptake can become a carbon credit: a module that adds to registry-approved reforestation and forest-carbon methodologies. For a national greenhouse-gas inventory, the same uptake is reported for completeness, and there it is not a credit, an offset, or a licence to emit.
Can you buy or sell this credit today?
No. Crediting is about one to two years out. 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?
No. 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?
Yes. It carries the same baseline, additionality, permanence buffer, and leakage accounting as the project's forest-carbon credits. Bark methane uptake lasts only while the forest stands, so it is buffered like the biomass credits rather than treated as a permanent removal. Measuring the flux precisely does not fix a weak baseline. The methane claim rests on the same baseline as the biomass credits, so a weak baseline weakens it too.
Does this double-count the forest's carbon?
No. Methane uptake is measured and credited separately from the biomass carbon a project already earns. SelvaFlux reports the two separately and does not add them together.
Does a project have to change how it manages the forest?
No. Bark methane uptake is something the forest already does. Measuring and crediting it adds a revenue line with no change in management on the ground.
Economics
Economics for a Forest Project
How much revenue does bark methane add to a forest project?
On the basis credited today (GWP100), it adds roughly 2 to 9% to a project's carbon revenue. Under GWP*, a metric that reflects methane's near-term warming, the same uptake would be worth about 10 to 40%. Registries do not credit on GWP* yet, so SelvaFlux shows that larger figure only as labelled upside.
How does it change the price a project needs to break even?
In SelvaFlux's project model, a reforestation project breaks even at a 12% return around $48 per tonne with no methane credit, $44 to $47 with the methane credit today, and $34 to $44 if GWP* were adopted. The effect is to lower the credit price at which a project becomes bankable.
Where do these numbers come from?
The uptake figures come from Gauci et al. 2024. The biomass growth and economic inputs come from published forest-carbon studies, including Cook-Patton et al. 2020. The break-even and revenue figures come from SelvaFlux's project model, with the full assumptions and sources listed on the Impact page.
Climate metrics
Measuring Methane's Warming
What is GWP*, and why does SelvaFlux use it?
GWP* is a way of expressing the warming from short-lived gases such as methane in terms that reflect their near-term effect (Allen et al. 2018; Lynch et al. 2020). SelvaFlux uses GWP* to describe climate benefit, because methane's warming is concentrated in the near term. Credits are still issued on GWP100, the metric registries use today, so the GWP* figure is shown only as labelled upside.
GWP100, GWP20, or GWP*: which one applies here?
Crediting today uses GWP100, about 27 times CO₂ for biogenic methane over 100 years. Methane's warming is much larger over a 20-year window. GWP* expresses the near-term benefit of a methane removal, on the order of 128 times CO₂ over 20 years in the framing SelvaFlux reports. SelvaFlux keeps the credited number (GWP100) and the climate-benefit number (GWP*) separate, and does not swap one for the other.
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 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?
That is a common misconception. A mature forest is roughly oxygen-neutral: it takes in about as much oxygen as it gives off, because respiration and decomposition consume roughly what photosynthesis produces. The case for keeping a forest standing rests on carbon, biodiversity, water, and now methane.
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.
About
About SelvaFlux
Who is behind SelvaFlux, and is the science credible?
The measurement science is published in Nature (Gauci et al. 2024), and SelvaFlux's founder is a co-author. The team's peer-reviewed work on terrestrial laser scanning and forest structure underpins the surface-area scaling that carries the flux to the whole forest.
Talk to the SelvaFlux Team
Pilot partners and buyers can reach us directly. For the full science and calculations, the Science and Impact pages carry the detail and sources.