Carbon crediting programs live or die on one question: Does a credit represent a real, additional tonne of carbon kept out of the atmosphere, or not? Get the rules too loose, and credits get issued for projects that would have happened anyway. Get them too rigorous, and few projects are actually implemented. Finding the right balance is slow, often thankless work. It’s also exactly the kind of work GHGMI’s Tani Colbert-Sangree recently did on an update to Washington State’s US Forest Protocol.
Washington Cap-and-Invest Forest Carbon Protocol
Washington’s Cap-and-Invest Program was created by the state’s Climate Commitment Act in 2021 and launched in January 2023 [1]. It caps greenhouse gas (GHG) emissions for the state’s largest polluters and requires them to cover their emissions using a mix of allowances (essentially permits to emit, sold at auction) and a limited share of carbon credits (which the program calls “carbon offsets”). The program is designed to help the state reach a 95% reduction in 1990-level emissions by 2050 [1].
Offsets can only cover a small slice of a company’s obligation, capped at 8% in the program’s first compliance period and dropping to 6% after 2027 [1]. To keep that slice meaningful, Washington’s Department of Ecology adopted a set of crediting protocols, several of which build on ones developed for the California Air Resources Board [2]. One of those is the U.S. Forest Protocol, which allows credits for reforestation, improved forest management, and “avoided conversion” projects, meaning forests that are protected from being logged or developed, often complemented by a conservation easement [2][3].
A Working Group And A Minority Position
A few years ago, Tani volunteered for a working group tasked with shaping Washington’s version of the US Forest Protocol within the state’s Cap-and-Invest forest carbon program. Inside that group, a familiar tension played out: some participants pushed for looser methodology requirements, arguing it would be easier for themselves and other project developers to implement and would bring more forest acreage into the program. Tani argued the opposite. He believed a more rigorous standard, even if it made projects more expensive and harder to develop, was the only way to have real confidence that the credits were doing what they claimed: keeping carbon-storing forests intact and acting as a reliable substitute for a company buying an allowance or making actual reductions in its emissions.
That position put him in the minority, with only a couple of others in the working group in his corner. Such is often the fate for volunteer working groups; financially interested participants (e.g., those who would stand to gain from the adoption of the US Forest Protocol in Washington State) are more likely to join than non-financially interested, objective observers. Tani didn’t back down.
Enter: The Problem With Appraisals
Avoided conversion credits depend on proving “additionality,” essentially showing that without the credit-funded protection, the land would have been converted to a higher-value use, such as development. That determination relies heavily on a real estate appraisal that estimates the land’s value. Appraisals, though, are notoriously subject to the judgment of whoever conducts them [5]. Two qualified appraisers can look at the same parcel of land and arrive at different numbers, and if a program only requires one appraisal, a project developer could select the most favorable one to share within their project documentation.
Tani pushed for a second independent appraisal to be a mandatory part of the determination and for the independent auditors who review projects for conformance to have experience reviewing land valuation appraisals. It wasn’t just about tightening a technical loophole. He pointed to the long, well-documented history of bias and discrimination in land valuation, the same dynamic that has devalued homes and neighborhoods based on the demographics of the people living there, and argued that a single appraiser’s judgment carries that same risk when it comes to valuing forested land. A lone appraisal gives one person’s potentially biased read on a property’s worth the power to decide whether a climate project qualifies at all. Requiring a second, independent appraisal was his suggestion for meaningfully reducing that risk.
California’s original protocol, which Washington was treating as a starting point, required only a single appraisal to meet this standard and placed no requirements on auditors to have this experience [4].
A Small Yet Impactful Victory
Washington’s Department of Ecology has since moved to require two independent appraisals from two different appraisers for avoided conversion projects going forward, rather than the single appraisal that California’s protocol allows [5][6]. The Department’s own rulemaking materials describe the change as a way to add “third-party verification of appraisal” to the protocol’s property valuation requirements [6], and outside groups reviewing the draft rule have specifically flagged the shift to two independent appraisals as a meaningful tightening of the program’s additionality standard [5].
“It meant a lot to see this land valuation issue get addressed in Washington’s revised protocol,” Tani commented. “Requiring two independent appraisals instead of one adds real cost and time to project development, but it will meaningfully help to prevent some non-additional projects from meeting the criteria.”
That means we can have more confidence in the impact of these credits on the climate, and make Washington’s US Forest Protocol’s implementation more equitable.
“If we want these credits to mean something, the rigor has to be there, even when it’s the harder path,” Tani pressed.
Who Gets to Decide What a Number Is Worth?
It’s easy to see rigor and accessibility as opposing goals in carbon markets. GHGMI’s view, and the one Tani pushed for in that working group, is that rigor is what makes carbon credits an effective climate policy tool.
A protocol that’s easy to use might give forest owners more revenue, which may be a positive benefit, but it comes at the expense of more reliably preventing forest loss. If the protocol isn’t preventing forest loss (because those landowners weren’t actually going to convert their lands if they didn’t receive carbon credit funding), then the protocol isn’t actually delivering climate benefit, no matter how many projects it approves. It’s also a reminder that technical-sounding fixes often trace back to plainer questions of fairness: whose judgment gets to set a number that matters, and what happens when that judgment goes unchecked.
Washington’s forest protocol update, expected to carry extra weight as the state moves toward linking its carbon market with California and Quebec [7], acknowledges this question of fairness and is a small but concrete step toward more effective climate policy.
Sources:
- Wikipedia, “Cap-and-Invest (Washington state)”: https://en.wikipedia.org/wiki/Cap-and-Invest_(Washington_state)
- The California US Forest Protocol was originally adapted from the Climate Action Reserve US Forest Protocol, with some changes made. The Washington State working group’s aim was to consider whether any changes to the California US Forest Protocol were warranted. Washington State Department of Ecology, “Offsets” overview: https://ecology.wa.gov/Air-Climate/Climate-Commitment-Act/Cap-and-invest/Offsets
- Washington State Department of Ecology, “Ecology issues the first Washington cap-and-invest offset credits”: https://ecology.wa.gov/blog/january-2024/ecology-issues-the-first-washington-cap-and-invest-offset-credits
- Climate Action Reserve, “Washington cap-and-invest offsets”: https://climateactionreserve.org/washington-cap-and-invest-offsets/
- Clean Air Task Force, “Washington released a draft forest offset rule, and there’s a lot to like”: https://www.catf.us/2025/08/washington-released-a-draft-forest-offset-rule-and-theres-a-lot-to-like/
- Washington State Department of Ecology, “Proposed Revisions to Ecology’s US Forest Protocol” (draft for public comment), Revision 5: property appraisal requirements
- International Carbon Action Partnership, “USA – Washington Cap-and-invest Program”: https://icapcarbonaction.com/en/ets/usa-washington-cap-and-invest-program
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