GAO Report Of 18 Expert Opinions On Climate Change Actions

Jun 9: The Government Accountability Office (GAO) released a letter report entitled, Climate Change: Expert Opinion on the Economics of Policy Options to Address Climate Change (GAO-08-605, May 9, 2008). The report was requested by Senator Barbara Boxer (D-CA), Chair of the Senate Environment and Pubic Works Committee, and Senator Dianne Feinstein, Chair of the Interior, Environment (including EPA) and Related Agencies Subcommittee of the Senate Appropriations Committee.

GAO was asked by the Senators to elicit the opinions of experts on: (1) actions the Congress might consider to address climate change and what is known about the potential benefits, costs, and uncertainties of these actions; and (2) the key strengths and limitations of policies or actions to address climate change. GAO worked with the National Academy of Sciences (NAS) to identify a panel of noted economists with expertise in analyzing the economic impacts of climate change policies and gathered their opinions through iterative, web-based questionnaires. The findings reported here represent the views of the 18 economists who responded to both questionnaires.

According to GAO, all of the panelists agreed that the Congress should consider using a market-based mechanism to establish a price on greenhouse gas emissions, and 14 of the 18 panelists recommended additional actions as part of a portfolio to address climate change, such as investment in research and development of low-emissions technologies. Experts differed on the initial stringency of the market-based mechanism, with 14 of the 18 panelists recommending an initial price between less than $1 and $20 per ton of emissions. In addition, 14 of 18 panelists were at least moderately certain that the benefits of their recommended portfolio of actions would outweigh the costs.

To establish a price on emissions, most of the panelists preferred either a tax on emissions or a hybrid policy that incorporates features of both a tax and a cap-and-trade program. A tax would set a fixed price on every ton of emissions, whereas a cap-and-trade program would limit or cap total emissions and establish a market for trading (buying and selling) permits to emit a specific amount of greenhouse gases.

Under the cap-and-trade system, the market would determine the price of emissions. A hybrid system differs from a traditional cap-and-trade system in that the government would cap emissions, but could sell additional emissions permits if the permit price rose above a predetermined level. Panelists also identified general categories of benefits, such as avoided climate change damages, and costs, such as increases in energy prices, associated with their recommended actions.

Overall the panel rated estimates of costs as more useful than estimates of benefits for informing congressional decision making, with some panelists citing uncertainties associated with the future impacts of climate change as limitations to estimating benefits. Further, the majority of panelists agreed that the United States should establish a price on greenhouse gas emissions as soon as possible regardless of the extent to which other countries adopt similar policies. At the same time, the majority of panelists said it was at least somewhat important to participate in international negotiations on climate change.

Panelists identified key strengths and limitations of alternative policy approaches that should be of assistance to the Congress in weighing the potential benefits and costs of different policies for addressing climate change. Many panelists said that a cap-and-trade program would be more effective in achieving a desired level of greenhouse gas emissions because, unlike a tax, it would provide certainty that emissions wouldn’t exceed a certain level. However, some of the panelists also said that taxes would be more cost-effective than a cap-and-trade program because the price of emissions would be certain and not susceptible to market fluctuations. Eight panelists therefore preferred a hybrid approach that incorporates features of both a tax and a cap-and-trade program. On average, the panelists rated cost effectiveness as the most important criterion for evaluating various policy options. Finally, panelists said an important strength of using a market-based approach is the ability for the government to raise revenue through a tax or the sale of emissions permits and to use that revenue to offset the adverse effects of the policy.

The 18 panelists included: Joseph Aldy, Resources for the Future; James Edmonds, Pacific Northwest National Laboratory; Richard Howarth, Dartmouth College; Bruce McCarl, Texas A&M University; Robert Mendelsohn, Yale University; William Nordhaus, Yale University; Sergey Paltsev, Massachusetts Institute of Technology; William Pizer, Resources for the Future; David Popp, Syracuse University; John Reilly, Massachusetts Institute of Technology; Roger Sedjo, Resources for the Future; Kathleen Segerson, University of Connecticut; Brent Sohngen, Ohio State University; Robert Stavins, Harvard University; Richard Tol, Economic and Social Research Institute; Martin Weitzman, Harvard University; Peter Wilcoxen, Syracuse University; and Gary Yohe, Wesleyan University.

Access the complete 81-page report (click here). [*Climate]