The American Electric Power coal burning plant in Conesville, Ohio, had a scrubber (a filtering system to limit emissions into the air) added to the unit seen emitting smoke in this photo. Photo: Michael Williamson / The Washington Post

By Chelsea Harvey
28 February 2017 (The Washington Post) – A hearing held Tuesday by several House subcommittees was meant to be an examination of the methods used to calculate an oft-contested metric known as the social cost of carbon, a way of quantifying the costs — environmental, health-related or otherwise — of emitting on additional ton of carbon dioxide into the atmosphere. Yet by its close, the conversation had disintegrated into yet another debate about the extent to which man-made climate change exists. It’s not the first time such an incident has occurred under the new Congress. Just a few weeks ago, the House Science Committee held a hearing intended to focus on the future of the Environmental Protection Agency and how it may incorporate the best available scientific evidence in its regulatory processes. At that hearing, multiple attendees took the opportunity to express doubt about the seriousness of human-caused climate change and the effectiveness of the EPA’s climate policies — many of which were developed with the social cost of carbon in mind.  The social cost of carbon is set at about $36 per ton of carbon dioxide. The calculations, developed by a federal working group in 2009, rely on a set of models that determine how carbon emissions may affect the climate in the future. They then calculate the monetary costs of any damages associated with those climatic changes, and have been used in dozens of federal environmental rules in the years since. Tuesday’s hearing, convened by the environment and oversight subcommittees of the House Science Committee, was intended to “examine the methods and parameters used to establish the social cost of carbon” with input from witnesses on how the calculation process could be improved. And indeed, the hearing did begin with a discussion of some of the common issues Republicans have raised about the calculation. These include the fact that the metric focuses on global costs, not just domestic ones, as well as concerns about the climate-related assumptions included in the models. Many conservatives have also criticized a component of the calculations known as a discount rate, suggesting it could be higher. (The discount rate is a kind of interest rate that helps reflect the fact that carbon emitted today may affect the climate years in the future.) At Tuesday’s hearing, many of these complaints were raised again by Republican members of the subcommittees and the witnesses they called to testify, including climatologist Patrick Michaels of the Cato Institute, statistician Kevin Dayaratna of the Heritage Foundation and economist Ted Gayer of the Brookings Institution. “The federal government should not include faulty calculations to justify faulty regulations,” said Rep. Lamar Smith (R-Tex.), chair of the House Science Committee, in his opening remarks. “Instead, it should eliminate the use of the social cost of carbon until a credible value can be calculated.” […] Such criticisms were contested during the hearing by Democratic attendees and witness Michael Greenstone, an economist at the University of Chicago and former chief economist for President Barack Obama’s Council of Economic Advisers, who helped convene the first federal working group to begin developing the social cost of carbon in 2009. In fact, many experts have suggested that the current value of the social cost of carbon has been underestimated. “The approach has been judged valid,” Greenstone said in his opening remarks at the hearing. “Last August, a federal court of appeals rejected a legal challenge to the metric. Furthermore, the Government Accountability Office has said the working group’s methods reflected key principles that ensured its credibility. It used consensus-based decision-making, relied largely on existing academic literature and models and disclosed limitations and incorporated new information by considering public comments and revising the estimates as updated research became available.” [more]

Members of Congress met to discuss the costs of climate change. They ended up debating its existence.