Global warming debate heats up as Jeb Bush clashes with President Obama

The Republican stance on manmade climate change has, historically, been resolute, if not entirely unanimous. Among the likely 2016 GOP contenders, candidates such as Ted Cruz, Rick Santorum, and Mike Huckabee have vigorously denied that humans are changing the climate, with Mr. Santorum calling it "a beautifully concocted scheme by liberals."

Not Jeb Bush.

"[T]he climate is changing," the former Florida governor and likely 2016 candidate said in comments made Wednesday, but, he added, it's not clear whether humans are to blame.

As he prepares to launch a presidential campaign, Mr. Bush is taking pains to forge a new, more moderate stance within the GOP on hot button issues on which the party has traditionally been unwavering.

"Look, first of all, the climate is changing. I don't think the science is clear what percentage is man-made and what percentage is natural. It's convoluted. And for the people to say the science is decided on, this is just really arrogant, to be honest with you," he said.

Bush's comments are at odds with many studies on the issue. The UN’s Intergovernmental Panel on Climate Change (IPCC) said in a 2013 report that it was 95 percent certain that more than half of the warming observed between 1951 and 2010 was manmade. 

But his comments, made during a campaign-centered house party in New Hampshire, were seen as a direct challenge to remarks President Obama made earlier Wednesday when he framed climate change as a threat to security.

"I’m here today to say that climate change constitutes a serious threat to global security, an immediate risk to our national security, and make no mistake, it will impact how our military defends our country," Mr. Obama said Wednesday.

In his State of the Union address earlier this year, Obama also emphasized the importance of climate change.

“No challenge  – no challenge  –  poses a greater threat to future generations than climate change,” Obama said on Jan. 20.

Bush dismissed Obama's claims, but in the same breath, proposed a new, science-forward approach for his party.

"I don't think it's the highest priority," he said of climate change, "I don't think we should ignore it, either. Generally, I think as conservatives we should embrace innovation, embrace technology, embrace science. It's the source of a lot more solutions than any government-imposed idea and sometimes I sense that we pull back from the embrace of these things. We shouldn't. We're the party that should be the party of discovery, the party of science, the party of innovation and tear down the barriers so that those things can accelerate in our lives to find solutions for all these things."

In downplaying its threat, Bush may be reflecting the attitudes of a majority of Americans.

A recent Gallup survey on the environment found that "global warming or climate change" ranks last among Americans' environmental concerns, with only 32 percent worrying about it a "great deal," down from 34 percent in 2014.

Nonetheless, in attempting to carve a new, more moderate Republican stance on climate change, Bush continued to get flak from the left – and from the right.

"Ninety-seven percent of climate scientists agree that human activity has led to climate change," Democratic National Committee national press secretary Holly Shulman said in a statement. "Ninety-seven percent. But Jeb Bush thinks they're wrong. Who's being intellectually arrogant now?"

But Republicans may not have been any better pleased by his comments than were Democrats. "Is Jeb Bush trying to alienate the Republican-conservative base even more than he already has?" wrote Investor's Business Daily's Kerry Jackson. "His comments about climate change and carbon dioxide emission cuts sure make it look that way."

Reaction to Bush's comments may explain why some Republicans – like New Jersey Gov. Chris Christie, who has acknowledged climate change – are now seen as avoiding the issue.