New Haven, Conn. –A national policy to cut carbon emissions by as much as 40 percent over the next 20 years could still result in increased economic growth, according to an interactive website reviewing 25 of the leading economic models being used to predict the economic impacts of reducing emissions.

Robert Repetto, an economics professor at the Yale School of Forestry & Environmental Studies who created the site, said, “As Congress prepares to debate new legislation to address the threat of climate change, opponents claim that the costs of adopting the leading proposals would be ruinous to the U.S. economy,” he said. “The world’s leading economists who have studied the issue say that’s wrong. And you can find out for yourself.”

The interactive website, www.climate.yale.edu/seeforyourself, synthesized thousands of policy analyses in order to identify the seven key assumptions accounting for most of the differences in the models’ predictions. It allows visitors to the site to indicate how likely they believe each of these assumptions is, and on that basis see what the economic models would predict.

Among the key assumptions are: Renewable energy technologies will be available at stable or improving prices; higher fossil fuel prices will stimulate energy-saving technological change; reducing U.S. carbon emissions will reduce economic damages from climate change and air pollution; and the United States will incorporate international trading of emission permits into its national policy. “The more visitors to the site think that these assumptions are likely, the more favorable the models’ predictions would be,” said Repetto.

Even under the most pessimistic assumptions, U.S. Gross Domestic Product would still grow by 2.4 percent per year, reaching $23 trillion by 2030 even if emissions are reduced by 40 percent below projected business-as-usual trends, compared to historical growth rates of 3 percent a year over recent decades. Under the most favorable assumptions, economic growth would rise slightly above 3 percent a year.

“The website shows that even under the most unfavorable assumptions regarding costs, the U.S. economy is predicted to continue growing robustly as carbon emissions are reduced,” said Repetto. “Under favorable assumptions, the economy would grow more rapidly if emissions are reduced through national policy measures than if they are allowed to increase as in the past.”

Descriptions of the 25 economic models used in the analysis can be found in The Costs of Climate Protection: A Guide for the Perplexed, published by the World Resources Institute in 1997, and The Costs of Greenhouse Gas Mitigation with Induced Technological Change: A Meta-Analysis of Estimates in the Literature, published by the Tyndall Centre for Climate Change Research in 2006.