Closed ncx-gitbot closed 1 year ago
NCX response: The business as usual model is a hierarchical statistical model that predicts one-year harvest risk and intensity based on FIA training data and a suite of covariates that include geographic, biological, economic, and sociological factors. Partial pooling across forest types ensures that the model is able to leverage the similarity and ubiquity of covariate relationships across the forests of the continental U.S. while still allowing for regionally specific differences.
Commenter Organization: EP Carbon
Commenter: Kyle Holland
2021 Deferred Harvest Methodology Section: No Section Indicated
Comment: The methodology over-credits baseline emissions by repeatedly counting the same avoided emissions year over year. The methodology is flawed because it models π β [0,1] where it should be modeled in π β [0,1/π] where π is the number of years in accounting. It is easy to show that the methodology over-credits baseline emissions by taking the sum of baseline emissions over π, that mathematically ββ ΞπΆπ2ππ π,π‘ π π‘=1 > πΆπ‘0 + πΆπ‘0 β πΊππ π,π‘ π π‘=1 when π > 1/π; that the sum of baseline emissions exceeds the total carbon stock including growth when π is greater than 1/π. This follows from simply writing the equation for a single landowner as the sum over time as follows: βΞπΆπ2ππ π,π‘ π π‘=1 = β[πΆπ‘0(1+ πΊππ π,π‘)(1 β π) βπΆπ‘0 ] π π‘=1 βΞπΆπ2ππ π,π‘ π π‘=1 = πΆπ‘0 (1 β π)β(1 +πΊππ π,π‘) π π‘=1 β ππΆπ‘0 And then substituting the upper limit on baseline emissions expressed as the opposite of reductions ββ ΞπΆπ2ππ π,π‘ π π‘=1 < πΆπ‘0 + πΆπ‘0 β πΊππ π,π‘ π π‘=1 which cannot physically exceed the total carbon stock over time and solving for π yields β[πΆπ‘0 (1 β π)β(1 + πΊππ π,π‘) π π‘=1 β ππΆπ‘0 ] β€ πΆπ‘0 + πΆπ‘0βπΊππ π,π‘ π π‘=1 ππΆπ‘0 β πΆπ‘0 (1 β π)β(1 + πΊππ π,π‘) π π‘=1 β€ πΆπ‘0 + πΆπ‘0βπΊππ π,π‘ π π‘=1 π β (1 β π)β(1 + πΊππ π,π‘) π π‘=1 β€ 1+ βπΊππ π,π‘ π π‘=1 β(1 β π)β(1 + πΊππ π,π‘) π π‘=1 β€ 1 + βπΊππ π,π‘ π π‘=1 β π π β 1 β€ 1 +β πΊππ π,π‘ π π‘=1 β π β (1 + πΊππ π,π‘) π π‘=1 π β€ 1 + β πΊππ π,π‘ π π‘=1 β π β (1 + πΊππ π,π‘) π π‘=1 + 1 And then conservatively assuming zero growth rate πΊππ π,π‘ = 0 π β€ 1 β π π +1 π β€ 1 οΏ½
Proposed Change: No Proposed Change