Page:Technical Support Document - Social Cost of Carbon, Methane and Nitrous Oxide Interim Estimates under Executive Order 13990.pdf/26

 {| style="width:36rem; margin-left: auto; margin-right: auto; border-collapse:collapse; border-top: 3px black; border-bottom: 1px solid black;" !style="border-collapse:collapse; border-bottom: 0px double black; margin:auto;" scope="col"| !style="border-collapse:collapse; border-bottom: 1px double black; margin:auto; text-align:center; font-weight:normal;" scope="col" colspan="4"| Discount Rate and Statistic !style="border-collapse:collapse; border-bottom: 1px double black; margin:auto; text-align:center; font-weight:normal;" scope="col" | EmissionsYear !style="border-collapse:collapse; border-bottom: 1px double black; margin:auto; text-align:center; font-weight:normal;" scope="col" | 5%Average !style="border-collapse:collapse; border-bottom: 1px double black; margin:auto; text-align:center; font-weight:normal;" scope="col" | 3%Average !style="border-collapse:collapse; border-bottom: 1px double black; margin:auto; text-align:center; font-weight:normal;" scope="col" | 2.5%Average !style="border-collapse:collapse; border-bottom: 1px double black; margin:auto; text-align:center; font-weight:normal;" scope="col" | 3%95$2$ Percentile !scope="row" style="text-align:center; font-weight:normal;"|2020 !scope="row" style="text-align:center; font-weight:normal;"|2025 !scope="row" style="text-align:center; font-weight:normal;"|2030 !scope="row" style="text-align:center; font-weight:normal;"|2035 !scope="row" style="text-align:center; font-weight:normal;"|2040 !scope="row" style="text-align:center; font-weight:normal;"|2045 !scope="row" style="border-collapse:collapse; border-bottom: 2px double black; margin:auto; text-align:center; font-weight:normal;"|2050
 * + Table 3: Social Costs of N$2$O, 2020 – 2050 (in 2020 dollars per metric ton of N$th$O)
 * style="text-align:center;"| 5800
 * style="text-align:center;"| 18000
 * style="text-align:center;"| 27000
 * style="text-align:center;"| 48000
 * style="text-align:center;"| 6800
 * style="text-align:center;"| 21000
 * style="text-align:center;"| 30000
 * style="text-align:center;"| 54000
 * style="text-align:center;"| 7800
 * style="text-align:center;"| 23000
 * style="text-align:center;"| 33000
 * style="text-align:center;"| 60000
 * style="text-align:center;"| 9000
 * style="text-align:center;"| 25000
 * style="text-align:center;"| 36000
 * style="text-align:center;"| 67000
 * style="text-align:center;"| 10000
 * style="text-align:center;"| 28000
 * style="text-align:center;"| 39000
 * style="text-align:center;"| 74000
 * style="text-align:center;"| 12000
 * style="text-align:center;"| 30000
 * style="text-align:center;"| 42000
 * style="text-align:center;"| 81000
 * style="border-collapse:collapse; border-bottom: 2px double black; margin:auto; text-align:center;"| 13000
 * style="border-collapse:collapse; border-bottom: 2px double black; margin:auto; text-align:center;"| 33000
 * style="border-collapse:collapse; border-bottom: 2px double black; margin:auto; text-align:center;"| 45000
 * style="border-collapse:collapse; border-bottom: 2px double black; margin:auto; text-align:center;"| 88000
 * }

Multiplying the SC-GHG in year t by the change in emissions in year t yields the monetized value of future emission changes from a year t perspective. This value must then be discounted to the present before being included in an analysis. For this purpose, the monetized value of future emission changes should be discounted at the same rate used to calculate the initial SC-GHG to ensure internal consistency—i.e., future damages from climate change using the SC-GHG at 2.5 percent should be discounted to the base year of the analysis using the same 2.5 percent rate.

As noted above, to correctly assess the total climate damages to U.S. citizens and residents, an analysis must account for both the impacts that occur within U.S. borders and spillover effects from climate action elsewhere. For the reasons discussed in Section 2 above, estimates focusing on the climate impacts occurring within U.S. borders are an underestimate of the benefits of GHG mitigation accruing to U.S. citizens and residents and, therefore, are not equivalent to a domestic estimate of the SC-GHG. (Section 2 also discusses why analyses should center their attention on a global measure of the SC-GHG). Additionally, models differ in their treatment of regional damages with one of the model developers recently noting that regional damages are “both incomplete and poorly understood” (Nordhaus 2017). The IWG further notes that the domestic focused SC-GHG estimates used under E.O. 13783 did not

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