2020-10-27_PERMIT FILE - C1981035 (22)

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have an outsized effect on potential forcing(CC2 is 99.9 percent+of COze). Due to this fact, BLM Colorado is limiting further downstream combustion estimates to COz only for the remainder of this report. BLM Colorado's approach for assessing climate impacts in NEPA has been to use the decision scope emissions as a surrogate (or proxy) for describing the known (modeled) climate impacts associated the with various global emissions scenarios. This approach has been adopted specifically because there are presently no climate analysis tools or techniques that lend themselves to describing any actual climate or earth system response (such as changes to sea level, average surface temperatures or regional precipitation rates) that would be attributable to the quantized emissions associated with any single action,decision, or scope. Contrasting proxy emissions at various scales relative to a quantity of emissions analyzed to have a definitive climate impact allows BLM to provide a relative sense for the intensity of the proxy emissions. Proxy emissions are estimated by projecting all of the reasonably foreseeable direct and indirect GHGs associated with the CARMMS scenarios(low and high)forward to two specific future years(Table 2.2-20). The study analyzed linear rates of oil, gas, and coal exploration and development (upstream) over a ten- year period which allowed for the annual average rates of emissions from the associated activities to be extracted and used in the projection calculations. Indirect downstream emissions(from product end use) are calculated for the same projection periods by applying EPA combustion emissions factors to the cumulative production estimates for each scenario. Projected production estimates are derived by applying the annualized AEO reference case growth rates for each mineral resource to the current resource production values obtained from ONRR. For the low scenario, the result should be consistent with the development projections made for CARMMS, which assumed an average development rate based on five years of historical data and captures recent technology advancements and current laws and regulations, similar to the AEC's reference case scenario. For the high scenario,the production estimates require an additional scaling factor based on the ratio of development between the low and high scenario such that BLM can account for the additional production that would be associated with higher annual average rates of oil and gas development. Coal production in CARMMS was held static across all scenarios for operational mines, and thus no additional scaling is required.The first projection period is being made for 2018 to 2032,and is designed to approximate a no growth, no reduction emissions scenario where the carbon budget is consumed in 14 years (based on current global emissions rates). The second projection period assumes steep emission declines to net zero in 2050, which also assumes the entire budget is consumed. Dunn Ranch Area LBA and Mining Plan Modification 44 Technical Resources Report