For Democrats vying to unseat President Trump, acknowledging climate change is easy. Deciding what to do about it is the hard part.

Among the 18 declared candidates, there is no broad consensus on taxing polluters on their carbon emissions — a measure most experts say is needed to slow global warming. And when it comes to building new nuclear power plants or adding federal regulations, there is even less agreement.

Those divisions were apparent in the candidates’ responses to a new climate policy questionnaire from The New York Times. They unanimously supported remaining in the Paris Agreement and restoring Obama-era policies that Mr. Trump has abandoned. But scientists are clear that preventing catastrophic climate change will require going well beyond those policies.

While the candidates agreed with that assessment, few offered detailed strategies for getting it done. Some have supported the Green New Deal in principle, but that congressional resolution was more a statement of ideals than a plan of action.