There are other questions on how to transition the broader global economy toward low-carbon development and how to balance public and private support, according to climate experts and organizations.

Stern also addressed a question on the role developing countries have to play in climate negotiations when developed economies like the US are often the largest emitters, citing China as an example of a developing country, but also one that has been active in its contributions to climate action.

"So the question is actually perfectly apt, because yes, the United States is, as the questioner asked, the second-biggest emitter. And the biggest emitter is China — nearly twice the size of the United States at this point. China is a developing country in the context of climate negotiations, and that's just an illustration of why we need to have both sides of this equation acting," he said.

He added that 60 to 65 percent of the current global emissions come from developing countries — which is a "good thing" because it means developing countries are developing — but that it also means climate change shouldn't come just from developed countries.

Representatives from close to 200 countries will gather in Paris next week to put together a global agreement cutting greenhouse gases. At a similar meeting in 2009 in Copenhagen, countries failed to reach agreement on how best to achieve global climate goals.

China's climate chief, Xie Zhenhua, said on Monday that "no country wants the situation in Copenhagen to be repeated" and that it would be best to leave the negotiating to the negotiators, as opposed to letting heads of state to resolve the problems. He told Reuters in an interview that he is confident there is now enough "political will" to achieve a new deal.