65% of economists surveyed favor an increase in Pigouvian carbon taxes for reducing greenhouse gas emissions.

63.1% of economists believe that increased reliance on nuclear power is another way to reduce greenhouse gas emissions.

However, the "median economist" believes that rising levels of greenhouse gases will result in less than 1% of loss to U.S. GDP per capita by the 2099.

http://www.bepress.com/ev/vol3/iss9/art1/