Fact-checking recent claims about climate change

In May, the White House released the National Climate Assessment, a report written by a committee of 60 scientists that assessed risks from man-made climate change including rising seas, extreme heat and dropping water supplies.

Separately, two science papers released in May reported that the global sea level will rise at least 10 feet, accelerating to a dangerous pace after the next century.

The reports sparked some much-publicized comments by politicians and pundits, making climate change a hot issue in elections this fall in some states.  

Here’s a summary of some of our recent fact-checks on climate change. We also fact-checked many claims before the recent flurry of media coverage sparked by the reports.

Sen. Marco Rubio

We have fact-checked a few climate change claims by or about Sen. Marco Rubio, R-Fla. The National Climate Assessment named Miami as one of the most vulnerable cities.

A day before the release of the scientific papers, Rubio told ABC’s Jonathan Karl on This Week on May 11, "I do not believe that human activity is causing these dramatic changes to our climate the way these scientists are portraying it."

An overwhelming majority of scientists agree that humans, by burning fossil fuels, contribute directly to global warming. A May 2013 report analyzing all scientific papers that address the causes of climate change showed 97.1 percent of the studies that took a position on global warming said that there’s been a negative human impact on the atmosphere. We rated Rubio’s claim False.

In a May 20 interview on Fox News, Rubio said that "surface temperatures in the earth have stabilized." He has a point that over roughly the past decade and a half, global surface temperatures have "paused," particularly compared to their rapid rise in previous decades. But scientists we interviewed agreed that the use of the word "stabilized" represents an unjustified leap from the data, since "stabilized" suggests that we have gotten through the worst of climate change.

At the very least, the uncertainty inherent in climate forecasting makes such a claim of "stabilization" premature. More likely, the evidence suggests that the "pause" in global surface temperatures is temporary, with temperatures poised to rise once the oceans start releasing more heat, such as during an El Nino event. It’s not clear when temperatures will rise again, but few scientists doubt that temperatures will rise again at some point. We rate Rubio’s claim Mostly False.

Organizing For Action, a group that backs President Barack Obama, had this to say about Rubio in 2013: "It’s time everyone in Florida knows: Sen. Rubio is a climate change denier."

In 2010, Rubio told the Tampa Tribune, "I don’t think there’s the scientific evidence to justify it." On four separate occasions in 2013 Rubio expressed opposition to climate change policies while speaking more cautiously about the science that proves climate change is happening. We rated that Mostly True.

Polling on climate change

We have fact-checked a few claims that relate to how Americans feel about climate change.

Joe Scarborough, host of MSNBC’s Morning Joe, said Rubio might be on relatively safe ground with the public.

"From 2004, 2005, 2006, Americans were bought in to the concept of climate change and that we need to move aggressively on it," Scarborough said.

But since then, the public shifted, he said.

"Check the polling: Most Americans began wandering away from this issue," Scarborough said.

Polls consistently showed dips through 2010; however, support for action on climate change has inched back in recent years. While the recent gains remain below the 2004 levels, the overall drop isn't as dramatic as Scarborough makes it sound. We rated this claim Half True.

U.S. Sen. Sheldon Whitehouse, D-R.I., has made dozens of speeches on climate change and PolitiFact Rhode Island has fact-checked a handful of them.

"Fifty three percent of young Republican voters -- Republican voters under age 35 -- said that they would describe a climate [change] denier as "ignorant,’ ‘out of touch’ or ‘crazy,’" Whitehouse said in a November 2013 speech. He cited the number accurately.

But the findings come from just one poll, commissioned by a conservation group. And the question he referenced focused only on the most extreme position of climate change
"deniers." We rated this claim Mostly True.

California wildfires, a climate change musical and other fact-checks

On ABC’s This Week, Gov. Jerry Brown, a Democrat, cited scientific research that links the increased number of fires to the state’s changing climate.

"It is true that there's virtually no Republican who accepts the science that virtually is unanimous. I mean there is no scientific question. There’s just political denial for various reasons, best known to those people who are in denial," he said May 18.

When it comes to on-the-record comments of members of Congress, Brown’s characterization is about right. We found at least eight Republicans in Congress who publicly voiced support for the scientific consensus and many more conservative legislators who deny either a human link to the changing climate, or the fact that the climate is changing altogether. We rated Brown’s claim Mostly True.

U.S. Rep. Lamar Smith, R-Texas, listed six National Science Foundation grants as questionable during a congressional hearing in March including one for a "climate change musical that was prepared for Broadway but I’m not sure ever was actually produced, $700,000." In 2010, the NSF awarded nearly that much to a Brooklyn-based theater company to develop "an innovative, out-of-the-box approach to exposing U.S. citizens to science," according to an NSF spokeswoman. PolitiFact Texas rated that statement True.  (The play ran in New York after our fact-check -- here’s a round-up of reviews.)

We have fact-checked several other claims related to climate change including about sea level rise in South Florida, fishing in Wisconsin,   the earth’s temperatures, and spending on climate change research. For a more complete list, see all of our fact-checks on the environment.

Spot a claim or attack about climate change worthy of a fact-check? Contact us at [email protected] or tweet us #PolitiFactThis