The episode follows a forest carbon credit from saw to ledger, starting with Douglas-fir disks cut at a Forest Service laboratory in Idaho. It traces tree models, the national plot inventory, and the equations that turn diameter into tonnes. In 2024 new equations made identical field data show forests 14.6 percent heavier. Credits are issued at a precision the tools lack, just as research is cut back.
Who's who
- Albert R. Stage+2 more episodesForest Service mensurationist who published the Prognosis model in 1973
- Jennifer JenkinsForest Service scientist behind the 2003 national biomass equations
- David ChojnackyForest Service scientist who updated the biomass equations in 2014
- James WestfallLead author of the 2024 National Scale Volume and Biomass system
- Grant DomkeCo-author of the analysis showing forests re-weighed 14.6 percent heavier
- Colin BeierCo-author of the 2024 analysis of the biomass step change
- Thomas M. Schultz Jr.Forest Service Chief who announced the March 2026 reorganization
Where it happens
- Moscow, Idaho+6 more episodesSite of the Forest Service Forestry Sciences Laboratory
- California+30 more episodesApproved Forest Vegetation Simulator for hundred-year forest credit projections
- Indiana+2 more episodesEstimated forest carbon rose 37 percent under the new equations
- Washington State+4 more episodesEstimated forest carbon fell 1.5 percent under the new equations
Timeline
- May 22, 1928The McSweeney-McNary Act authorizes the Forest Survey, origin of today's inventory.
- June 1973Albert Stage publishes the Prognosis Model for Stand Development.
- 2003Jenkins and colleagues publish national biomass equations.
- 2024New national equations make America's forests 14.6 percent heavier from the same field data.
- March 31, 2026The Forest Service announces a reorganization with research facility closures.
- April 15, 2026An independent University of Maryland inventory puts the forest sink at 14.6 percent of emissions.
Still debated
Whether the jump in the national forest sink was mostly due to the new equations is plausible but not proven, since the inventory also recalculated other categories. The three published sink figures also come from different years and methods, so they are not strictly the same trees.
