"The world has made transitions from one type of energy source to another … in the 75- to 125-year kind of timeframe. We don't have that luxury here. We have to hurry history."

Steve Cochran, Environmental Defense Fund, Washington DC

"However you want to cut it — if we're going to get serious about climate-change policy, we're going to have to change the prices of fossil fuels."

Joseph Aldy, fellow, Resources for the Future and co-director of the Harvard Project on International Climate Agreements, Washington DC

"We need … to identify in very concrete terms, not just in a sort of warm and fuzzy way, what new investments in the energy sector mean: where those dollars would go, where those jobs would be created, where an auto worker who is currently making an SUV will now be making a hybrid transmission."

Steve Cochran

"If we put too much money into energy R&D over too short a period of time, there is going to be waste."

Richard Newell, professor of energy and environmental economics, Duke University, Durham, North Carolina

"We need to have a diversified portfolio of R&D [and] we shouldn't pick just one winner. Having said that, let me pick a winner right now … carbon capture and storage."

Joseph Aldy

To hear the full discussion, chaired by our columnist David Goldston (see page 15), visit http://www.nature.com/nature/podcast Future podcasts in this series will cover biomedical research and innovation policy.