In an exchange that would have been all but unthinkable even four years ago, moderator Jake Tapper posed a question to Florida senator Marco Rubio and New Jersey Governor Chris Christie that quoted Reagan secretary of state George Schultz: “Why not take out our insurance policy and approach climate change the Reagan way?”

But despite the token question well into the third hour of CNN’s GOP debate, no candidate was willing to endorse any possible solution.

“Here’s the bottom line,” Rubio answered. “Every proposal they put forward will make it harder to do business in America. Harder to create jobs in America. Single parents are already struggling across this country to provide for their families. Maybe a billionaire here in California can afford an increase in their utility rates, but a working family in Tampa, Florida or anywhere across the country cannot afford it.”

He said: “We are not going to destroy our economy, make America a harder place to create jobs, in order to pursue a policy that will do nothing, nothing to change our climate, to change our weather.

“America is a lot of things – the greatest country in the world, absolutely. But America is not a planet.”

Christie, who has previously stated that he believes climate change to be real, demurred when asked if he had an answer to “sceptics” like Rubio. “I don’t think Senator Rubio is a sceptic on climate change,” he said. “I think what Senator Rubio said I agree with – that in fact we don’t need this massive government intervention to deal with the problem. Look at what we’ve done with New Jersey – we’ve already reached our clean air goals for 2020.” He pointed to 53% of New Jersey’s power coming from nuclear energy.

“I agree with Marco. We shouldn’t be destroying our economy in order to chase some wild leftwing idea that somehow us by ourselves is going to fix the climate. We can contribute to that and be economically sound.”

Both Rubio and Christie, and later Walker, accepted the premise that the climate was changing. But Rubio felt there was nothing a government intervention could do about it.

“Here’s what we should be sceptical of: we should be sceptical of decisions the left wants us to make,” Rubio said. “They will not do a thing to lower the rise of the sea, they will not do a thing for the drought here in California, but what they will do is make America a more expensive place to create jobs … I am not in favour of anything that will make it harder for [Americans] to raise their families.”

Scott Walker echoed Rubio in worrying that “we’re going to put people – manufacturing jobs – this administration is going to put them at risk”.

At the start of the debate, Rubio startled many by bringing up the environment – in what turned out to be a joke.

“I’m aware California has a drought,” Rubio said. “That’s why I brought my own water bottle.”