Technical Support Document: Social Cost of Carbon, Methane, and Nitrous Oxide - Interim Estimates under Executive Order 13990
The Interagency Working Group (IWG) on the Social Cost of Greenhouse Gases, recently reconvened under the auspices of Executive Order 13990, released a new technical support document with interim estimates on the social costs of carbon, methane, and nitrous oxide. According to the new document, released on February 26, 2021, the IWG guides agencies to revert to the four sets of values based on three discount rates (2.5%, 3%, and 5%) as were used from 2010 through 2016, which had been subject to public comment. The IWG notes that new data and evidence strongly suggests that the appropriate discount rate for intergenerational considerations is lower.
The estimates in the new technical support document are reported in 2020 dollars, but are otherwise identical to those presented in the most recent previous version of the technical support document and its addendum. The ‘central’ 3% estimates for carbon dioxide emissions occurring in year 2025 is $56 per metric ton. The ‘central’ estimates for year 2025 methane and nitrous oxide emissions are $1700 and $21,000, respectively.