Take on a podcast episode from Reversing Climate Change, originally published Thu, 07 Ma. Listen: https://podcasters.spotify.com/pod/show/reversingclimatechange/episodes/398-Scientists-vs--Engineers---the-Commercial-Pressure-on-Carbon-Dioxide-Removalw-Erica-Dorr--Samara-Vantil--Rainbow-e3j0jq0

TL;DR

  • Rainbow’s head of science Erica Dorr and certification engineer Samara Vantil reframe the science-vs-engineering split as a false binary; both do applied work daily.
  • The real gap is technical-vs-commercial. Useful framing for anyone who’s watched a salesperson promise a methodology change on a call.
  • Concrete example: biochar lab samples cost ~€600 to ship Africa→Europe. That’s the kind of number that should anchor measurement, reporting, and verification (MRV) requirement-setting.
  • Defense of Charm’s “cut scope” posture as courage, not laziness — diminishing returns on the last sample are real and worth saying out loud.
  • When project developers can’t deliver a data point, Rainbow’s default is a conservative discount factor, not rejection. Worth knowing if you’re a buyer reading their credits.

Ross Kenyon hosts Erica Dorr (head of science) and Samara Vantil (environmental engineer, certification) of Rainbow, the carbon removal standard and registry. The episode is a follow-up to two essays Kenyon wrote for Rainbow on whether durable CDR needs more field engineers or more scientists, and lands somewhere more interesting than either piece: the science/engineering line is fuzzy, and the harder boundary is between technical teams and commercial.

The load-bearing claim is about where rigor actually gets negotiated. Dorr describes methodology development as a quadrant: how sensitive is the outcome to a given requirement, and how hard is it to obtain the data? Low sensitivity / low difficulty: require it, no harm done. High sensitivity / high difficulty is where the team spends its uncomfortable time. Vantil’s biochar leakage example is the cleanest illustration — Rainbow concluded a discount factor was warranted, knew the developer would issue fewer credits as a result, and shipped it anyway. The €600-per-sample shipping cost from African biochar sites to European labs is the kind of operational number that almost never makes it into MRV discourse, and it should: it’s the actual constraint shaping how many samples a methodology can credibly demand.

The more provocative bit is Kenyon’s defense of Charm Industrial’s recent “cut scope” posture (Peter Reinhardt’s argument for sampling less). Kenyon frames this against the “race to the bottom” critique and lands on the economist’s point that the optimal number of travel deaths is non-zero — there is no non-arbitrary line on quality, only a curve where each marginal unit of certainty costs more than the last. Dorr agrees, with the engineer’s caveat: a conservative discount on credits issued is preferable to chasing the last 1% of accuracy, provided you’re not over-issuing. That’s a reasonable position, but it puts a lot of weight on registries being honest about where on the curve they’re actually operating — and on buyers being able to tell.

For context, this sits alongside ongoing arguments about Isometric, Puro.earth, and Frontier’s diligence approach over how much MRV burden a methodology can bear before projects become uneconomic. Rainbow’s pitch — that conservative discounts plus field-aware requirement-setting beats either rejecting projects or over-promising precision — is a coherent position in that debate. Whether buyers reward it is a separate question.

Useful for: methodology authors, registry staff, and CDR buyers who want to hear two technical people talk honestly about the commercial pressure on rigor without either capitulating to it or pretending it doesn’t exist. Skip if you want quantified durability numbers — this is about process, not pathways.