Source: Washington UTC, September 20, 2019
On Sept. 12, the Utilities and Transportation Commission adopted social cost of carbon estimates that utilities will use to comply with the package of clean energy legislation signed into law by Gov. Jay Inslee in 2019.
The social cost of carbon calculates the broad array of economic and social damage caused by carbon and other greenhouse gas emissions.
In docket U-190730, the commission adopted cost estimates produced by the Interagency Working Group onSocial Cost of Greenhouse Gases. The commission adjusted this rate to reflect 2018 dollars using the U.S. Dept. of Commerce GDP price index, outlined in the following table:
Adjusted Cost of Greenhouse Gas Emissions
| Year | Social Cost of CO2* (in 2007 dollars) | ** GDP Index (2007) | ** GDP Index (2018) | Adjusted Social Cost of CO2 (in 2018 dollars) |
| 2010 | 50 | 92.498 | 110.382 | 60 |
| 2015 | 56 | 92.498 | 110.382 | 67 |
| 2020 | 62 | 92.498 | 110.382 | 74 |
| 2025 | 68 | 92.498 | 110.382 | 81 |
| 2030 | 73 | 92.498 | 110.382 | 87 |
| 2035 | 78 | 92.498 | 110.382 | 93 |
| 2040 | 84 | 92.498 | 110.382 | 100 |
| 2045 | 89 | 92.498 | 110.382 | 106 |
| 2050 | 95 | 92.498 | 110.382 | 113 |
* Social cost of carbon in 2007 dollars using the 2.5% discount rate, listed in table 2, technical support document: Technical update of the social cost of carbon for regulatory impact analysis under Executive Order No. 12866, published by the interagency working group on social cost of greenhouse gases of the United States government, August 2016.