The social cost of carbon (SCC) is an estimate of the cost (and benefit) to society caused by the emission of a marginal ton of CO2. This estimate is useful for applications such as carbon taxes and measuring the cost/benefit of other climate regulations and policies. The SCC estimate can vary based on the time-frame considered, time discounting, climate models, forecasting growth of zero-carbon energy and carbon capture, and different models of social harms from climate change. Given this complexity, climate experts often publish ranges of the social cost of carbon, according to different assumptions and models.

On February 26, 2021, the Interagency Working Group (IWG) on the Social Cost of Greenhouse Gases convened by the Biden Administration released an initial report giving estimates on the social cost of carbon in 2020, suggesting $51 per ton of CO2 at a 3% annual discount rate, with estimates ranging from $14 to $76 per ton of CO2 based on different discount rates. The Trump Administration previously estimated the SCC at $1 to $6 in November 2017. The IPCC gives several estimates for SCC, depending both on the year the CO2 is emitted and for different warming scenario targets. Their 2018 report estimated the SCC in 2030 for an under 1.5°C pathway range from $171 to $7680 (in 2021 USD).

President Joe Biden issued Executive Order 13990 in January 2021, reconvening the IWG and requesting that they issue a final report on SCC in January 2022.