Karen Frantz
GHG Monitor
12/06/13
The White House is calling for public comment on technical corrections made to its revised Social Cost of Carbon estimates—used to gauge the future social and economic costs of emitting a ton of carbon into the atmosphere—following months of outcry from Republicans and industry groups over charges of a lack of transparency in the SCC revision process. A technical support document published in the Federal Register Nov. 26 delves into the data behind the controversial revision and offers details on new versions of three assessment models that are among those used to calculate the SCC estimates, known as DICE, PAGE and FUND, all of which had been updated since the initial SCC figures the government began using were released in 2010.
The document states, “The model updates that are relevant to the SCC estimates include: an explicit representation of sea level rise damages in the DICE and PAGE models; updated adaption assumptions, revisions to ensure damages are constrained by GDP, updated regional scaling of damages, and a revised treatment of potentially abrupt shifts in climate damages in the PAGE model; an updated carbon cycle in the DICE model; and updated damage functions for seal level rise impacts, the agricultural sector, and reduced space heating requirements, as well as changes to the transient response of temperature to the buildup of GHG concentrations and the inclusion of indirect effects of methane emissions in the FUND model.”
The 2010 SCC estimates were based on versions of DICE, FUND and PAGE from 2007, 2009 and 2002 respectively, whereas the updated SCC estimates released in May were based on DICE, FUND and PAGE versions from 2010, 2012 and 2009 respectively. When the original SCC figures were released, the Interagency Working Group on Social Cost of Carbon recommended that the estimates be revisited as the assessment models were updated.
60-day Comment Period
The public comment period will last for 60 days, but that may not be enough for some lawmakers. In a Nov. 26 letter to the White House Office of Management and Budget, representatives John Culberson (R-Texas), Nick Rahall (D-W.Va.), Duncan Hunter (R-Calif.) and Gene Green (D-Texas) asked for a longer commenting period. “A 120-day comment period is required to perform legal and economic analysis on the assumptions underlying the social cost of carbon calculation including discount rates and technological innovation and its deployment,” the letter states. “Providing stakeholders with adequate time to run cost models and file substantive comments will provide a more meaningful review of the benefit-cost analysis employed in determining the social cost of carbon.”
