But a group of Republicans — Romney and Sens. Lamar Alexander (Tenn.) and Lindsey Graham (S.C.), who worked with Democrats in 2009 and 2010 to cap carbon emissions, as well as others — have taken it upon themselves to come up with market-based approaches to addressing climate change.

“There’s no question that we’re experiencing climate change and that humans are a significant contributor to that,” Romney told The Hill. “In my view, the course forward is going to require innovation and technology breakthrough because nothing I’ve seen is going to reverse the warming trend other than that.”

“We’ve spoken about some ideas as to how we might encourage that,” Romney said of his conversations with GOP colleagues.