ncx-gitbot
commented
1 year ago NCX response: We agree that accounting for uncertainty is very important in any forest carbon project. Our revised methodology accounts for and requires a deduction associated with the uncertainty of carbon stocks in the project and baseline scenarios.
Commenter Organization: EP Carbon
Commenter: Kyle Holland
2021 Deferred Harvest Methodology Section: No Section Indicated
Comment: The methodology fails to acknowledge the complete uncertainty in baseline harvest emissions when FIA data are used to estimate both initial carbon stocks and the harvest risk model. Provided that baseline emissions are simply the product of a imperfect estimate for π and an initial quantity of carbon stock as shown by ΞπΆπ2ππ π = βππΆπ‘0 , the accounting further ignores the covariance of these two random variables, further compounding the uncertainty in the calculation of ΞπΆπ2ππ π,π‘ . If both the quantity of π and the quantity of πΆπ‘0 are estimated from the sample, say both from FIA data, then these two quantities are not statistically independent. The total uncertainty including the covariance factor in ΞπΆπ2ππ π,π‘ should therefore be quantified to include a measure of the covariance between estimates of π and πΆπ‘0 , or the methodology should prohibit the use of the same sample data in estimating the quantities of π and πΆπ‘0 as an applicability condition. The potential magnitude of the absent consideration of covariance could be very large, which underscores the need to fully quantify the uncertainty in ΞπΆπ2ππ π,π‘ . Equations 16 and 18, along with Table 11-1 identify eleven factors that are used to estimate the harvest risk factor π. Of these eleven factors, model parameters for as many as eight of the factors could be estimated from FIA data. Given that crediting is largely a function of only two random variables, not fully quantifying and accounting for the covariance uncertainty of these two variables presents a significant risk of over crediting.
Proposed Change: No Proposed Change