Field measurement
How We Measure the Uptake
A credit is more than a single measurement. It is a methane uptake figure for the whole site, with a stated uncertainty, that an independent auditor can check and that can be reproduced year after year. That takes a measurement system built for repetition, not a one-off reading.
- 01
Set Up Sampling Infrastructure
A credit requires the same forest to be measured again and again over years, so each measurement has to be efficient and consistent. We set up sampling infrastructure of our own design and build across each site, and train local crews to run it, so the forest can be remeasured reliably over time.
- 02
Measure the Methane Flux
We measure the actual methane flux at the bark with scientific-grade instrumentation. Each reading is a direct measurement of the gas exchange, recorded with quality-control checks so the data hold up to an audit.
- 03
Map the Variation, Then Sample Where It Counts
Uptake varies across space, time, species, and other factors. We measure intensively at first to quantify that variation, then concentrate sampling on the factors that drive it, which narrows the confidence interval of the whole-site estimate for the least measurement effort. In practice we revisit each site several times in the first year and less often as the picture firms up.
- 04Laser scanning
Scan and Reconstruct the Forest
We scan each site with terrestrial laser scanning and reconstruct it in three dimensions. From the point cloud we separate the individual trees, fit structural models to each, and compute their woody surface area. These methods build on laser-scanning research we have helped develop and publish.
- 05
Produce the Whole-Site Number
Combining the flux measurements with the woody surface area gives methane uptake for the whole site over time, with a stated confidence interval. That is the number a project is credited on.
Published science
What Is Already Published
That forests take up methane through their bark, and that it can be measured and scaled by woody surface area, is established in the peer-reviewed literature and independently corroborated by other groups. The science page lists that corroborating work.
Status
Where This Stands Today
We are measuring at pilot sites in the tropics, building the evidence base and refining our models of how methane uptake varies across space and time. The first methodology rests on these manual measurements at project sites. As the data deepen, we move to a digital methodology that scales with less fieldwork. Crediting is a year or two away, and projects that begin measuring now will have a verified record in place when it opens.