This week in climate change, former Hewlett-Packard CEO Carly Fiorina, who has frequently asserted, “a single nation acting alone will make no difference at all” in the effort to solve climate change, dismissed the international climate change negotiations, which started this week in Paris.

“If you read the fine print of the science, what the scientists tell us, all those scientists who say climate change is real and manmade, they also tell us… that it would take a concerted global effort over 30 years costing trillions of dollars,” she said. “I think the likelihood is near zero. So no, I don’t think [the Paris climate conference] is very productive.”

Frontrunner Donald Trump called President Obama’s position that climate change poses a threat to national security one of the “dumbest statements” ever made in politics. When pressed on what he would do on climate change as president, Trump responded: “I want to make sure we have clean air and we have clean water,” he said. “That is my thing on climate change.”

“If you’re talking about global warming or climate change, you have to make the whole world behave,” Trump concluded.

Later in the week, in an interview with Bill O’Reilly, Trump said, “I don’t believe what they say. I think [climate change] is a big scam for a lot of people to make a lot of money.”

Speaking from New Hampshire, Florida Sen. Marco Rubio said “there has never been a time when the climate hasn’t been changing, and what percentage of that is due to man’s activity is not something there’s a consensus is on.”

“I’m a policymaker,” Rubio added. “My job is to go through the different solutions that they present to us. I can tell you that all the changes they’re presenting to us would do nothing, even according to the scientists, would do nothing to change our climate, especially in the United States, but would have a dramatic impact on our economy.”

In a separate interview, Rubio expressed skepticism that progress will be made in ongoing climate negotiations in Paris.

“All the growth in carbon emissions over the next 30 years is going to come out of India and China and other developing countries. And they don’t intend to do anything about it no matter what document they are going to sign.”

“I don’t think they are going to arrive at any measures that are going to solve any problem” in Paris, Rubio added.

New Jersey Gov. Chris Christie talked about his views on climate change and the level to which he regards the issue as a crisis.

“The climate’s always changing, and we cannot say that our activity doesn’t contribute to change in the climate,” Christie said. “What I’m saying is: it’s not a crisis. The climate’s been changing forever and it will always change, and man will always contribute to it.”

When pressed on what scientists agree with him that climate change is not a crisis, Christie responded, “listen, there are a lot of scientists who agree with me that climate change is real, occurs and that men and women contribute to it… I didn’t say I was relying on any scientists… I don’t see evidence that it’s a crisis.”

Speaking in Iowa, former Florida Gov. Jeb Bush expressed uncertainty over whether he would have attended the climate change conference in Paris.

“I’m not sure I would have gone to the climate summit if I was President today,” Bush said. “I worry about the economic impact for our country. I worry that, put aside intentions, that this, these proposals could have an impact on the here and now, on people that are really struggling right now.”

“So I’d be uncertain whether I’d attend a meeting like that, where it seems like the movement is towards policies that would hurt our economy,” he added.

On the other hand, Ohio Gov. John Kasich said that he would attend global climate conferences as president, but would not work on a pact toward reducing greenhouse gas emissions. Kasich spoke to RepublicEN at a town hall event in Iowa, where our climate fellow dared to ask him if free enterprise can solve climate change.

“Oh, I think that there are technologies that are coming down the road that are going to be very effective, including batteries, when we get that in place…. I think that battery technology, solar, wind, all these alternatives; they’re good, we need to work on all of them.”