PolitiFact abets witch hunt for ‘climate change deniers’

PF National2“Organizing for Action said that Rubio ‘refuses to accept the basic science’ on climate change and is ‘a climate change denier.’

… We rate the statement ‘Mostly True.'”

—PolitiFact, Aug. 16, 2013



PolitiFact’s ruling defies logic and sets aside its own standards.

The Facts

PolitiFact used an email from OFA’s Ivan Frishman as the subject of its fact check.  We haven’t located a full version of that email published to the Web, so we’ll have to stick with PolitiFact’s telling:

“Friend —

“We’re spending the next week of Action August getting serious about climate change.

“To get ready, we’re calling out Sen. Marco Rubio, who refuses to accept the basic science on this issue — and is standing in the way of action.

“It’s time everyone in Florida knows: Sen. Rubio is a climate change denier.”


PolitiFact also reports OFA’s justification for its charge against Rubio:

In supporting its claim, OFA cites a Feb. 13, 2010, article in the Tampa Tribune.

According to the Tribune, Rubio called his then-Senate opponent Charlie Crist “a believer in man-made global warming” and said, “I don’t think there’s the scientific evidence to justify it.”


As noted above, PolitiFact rates OFA’s charge “Mostly True.”

Analyzing the Rhetoric

On August 21 Zebra Fact Check published its own ruling on OFA’s claim that Marco Rubio qualifies as a “climate change denier.”  We found the claim false.  Clearly a discrepancy exists between the two rulings.  We’ll explain why we ruled correctly and how PolitiFact erred.

1) The consensus problem

Note that OFA calls out Rubio for failing to accept “the basic science” on climate change.  Partly in preparation for this fact check, Zebra Fact Check looked into the research used to bolster claims of a scientific consensus on climate change.

If a consensus exists on the share of responsibility humans bear for causing climate change, none of the existing studies have measured it.  A 2008 study by Dennis Bray and Hans von Storch found that 84 percent of the scientists surveyed believed humans account or would soon account for most climate change, counting responses higher than 4 on a scale of 1-7.   But that’s the opinion of scientists, not “basic science.”  The survey data show an uncertainty about the extent to which humans are responsible for observed climate change.  For example, the von Storch study found 35 percent of respondents “very much” convinced that humans do or will soon account for most of climate change.

2) The “basic science” problem

PolitiFact did very little to examine and define the “basic science” aspect of the fact check.  Instead, PolitiFact, without explaining its action, simply defined for its readers what it called the applicable definition of climate change:

We should clarify up front: In the policy context, the term “climate change” refers to rising temperatures and sea levels caused by human beings and their use of carbon-dioxide-emitting fossil fuels.


PolitiFact apparently assumed that the policy context applies, not the “basic science” context.  And PolitiFact’s definition does not in any way pin down the extent to which humans contribute to climate change via increases in atmospheric carbon dioxide.  If we fail to pin down this detail, then Rubio can only qualify as a “denier” if he claims humans do not contribute to climate change.

3) Rubio’s claims and the clarity and chronology problems

PolitiFact found a pair of statements from Rubio that it uses to support its “Mostly True” ruling, with the primary evidence coming from the Tampa Tribune.  The Tribune conducted an interview with Rubio and published parts of it on Feb 10, 2010:

In an interview with the Tribune on that subject Friday, Rubio called Crist “a believer in man-made global warming.”

“I don’t think there’s the scientific evidence to justify it,” Rubio said.

Asked whether he accepts the scientific evidence that the global climate is undergoing change, he responded, “The climate is always changing. The climate is never static. The question is whether it’s caused by manmade activity and whether it justifies economically destructive government regulation.”


Perhaps Rubio’s clearest statement on climate change comes from a Feb. 5, 2013 interview with BuzzFeed’s Ben Smith:

[T]he climate’s always changing.  That’s not the fundamental question.  The fundamental question is whether man-made activity is what’s contributing most to it.  And I understand that people say there’s a significant scientific consensus on that issue, but I’ve actually seen reasonable debate on that principle.


In the second statement, Rubio appears to take for granted a human role in climate change but points to uncertainty about the share attributable to human actions.  His statement aligns with the consensus view found in the von Storch study.

Two rules of interpretation would apply.  First, interpret an unclear statement according to a more clear statement by the same source.  Second, in judging what a person thinks in the present place greater weight on more recent statements.

PolitiFact’s statement of principles appears to implicitly recognize the above principles, especially the second:

Timing – Our rulings are based on when a statement was made and on the information available at that time.


OFA could presumably consider Rubio’s 2013 interview statement if it wonders if he denies the basic science of climate change.  And even if OFA does not consider Rubio’s more recent statement we can trust fact checkers to correct the oversight.  Yet PolitiFact offers no sign it applied the above principles.  PolitiFact places its priority on interview snippets from 2010 over a full interview from 2013.  OFA reaps the benefit of PolitiFact’s failure.

Keeping the focus on the main issue

We call Rubio’s comments in the Tribune interview ambiguous.  We’ll explain the reasoning behind that judgment, but first we will emphasize that the main point is Rubio’s clear statement in 2013.  Even if Rubio had clearly said “I categorically deny climate change” in 2010, it’s appropriate to judge his current stance on climate change by what he said more recently.

Rubio said “I don’t think there’s the scientific evidence to justify it.”  Why isn’t that clear?

Rubio clearly said the scientific evidence was lacking for something.  That something was “it.”  The Tribune story places the quotation right after Rubio’s quote about Crist, calling the Florida governor, then a Republican, “a believer in man-made global warming.”

Was “it” man-made global warming?  Does “man-made global warming” imply that human activity causes more than half of the warming effect?

The Tribune writer, William March, told us that he believes he no longer has a digital record of the Rubio interview.  March said he tried to include in his story everything Rubio said during the interview that directly related to his beliefs on climate change.  March also said he believes Rubio was talking about “man-made global warming” when the latter said “I don’t think there’s the scientific evidence to justify it.”

Unfortunately, that doesn’t tell us whether “man-made global warming” implies a greater role for human agency than “climate change.”  Given Gov. Crist’s advocacy for policy measures intended to reduce greenhouse gas emissions, we think “man-made global warming” implies a dominant role for human activity.  The “basic science” of climate change does not yet include a dominant role for human activity.

This view of Rubio’s position also fits well the views he expressed in 2009 to the Miami Herald:

Now, the former West Miami legislator is raising questions about whether climate change is man-made.

“I’m not a scientist. I’m not qualified to make that decision,” Rubio said Thursday. “There’s a significant scientific dispute about that.”


As with the Tribune story, we don’t get enough context to confirm Rubio means climate change when he talks about the “scientific dispute.”  An email to the Herald writer asking for a transcript or other details drew no response.

Our examination of the evidence gives us an undefined “basic science,” a poorly defined “climate change” and a strong term, “denier,” applied to a senator who in 2013 affirmed the basic science that human activity contributes to climate change.


It’s “Mostly True” that “Rubio ‘refuses to accept the basic science’ on climate change”

icon False FallacyIcon Ambiguity

Though PolitiFact’s claim is false in light of Rubio’s 2013 affirmation that human activity contributes to climate change, it works effectively as a deception through the fallacy of ambiguity.  With “climate change” ill-defined and basic science undefined, an audience unaware of the basic science of climate change may accept the charge as true.

It’s “Mostly True” “Marco Rubiois ‘a climate change denier.'”

icon False FallacyIcon Ambiguity One-Sideness

PolitiFact provided no unequivocal evidence Rubio denies climate change, and ignored the relevance of good evidence to the contrary.  PolitiFact misleads its audience through a fallacy of ambiguity, augmented with a fallacy of one-sidedness.

We considered offering a charitable interpretation, that “climate change” means that most or all of recent climate change results from human activity.  But that interpretation does not count as the basic science of climate change.  The size of the human contribution to recent warming is not yet known as a matter of basic science.  And even under that charitable interpretation Rubio counts as a skeptic, not a denier.



Jacobson, Louis. “Group Backing Barack Obama Says Marco Rubio Is a “climate Change Denier”PolitiFact. Tampa Bay Times, 16 Aug. 2013. Web. 06 Sept. 2013.

March, William. “Rubio: Global Warming Not Caused by Humans.” TBO.com. Tampa Media Group, LLC, 12 Feb. 2010. Web. 06 Sept. 2013.

White, Bryan W. “OFA and the ‘Climate Change Deniers’.” Zebra Fact Check. Zebra Fact Check, 21 Aug. 2013. Web. 06 Sept. 2013.

White, Bryan W. “Making Sense of the Claims about Climate Change Consensus.” Zebra Fact Check. Zebra Fact Check, 29 Aug. 2013. Web. 06 Sept. 2013.

Adair, Bill. “Principles of PolitiFact and the Truth-O-Meter.” PolitiFact. Tampa Bay Times, 21 Feb. 2011. Web. 06 Sept. 2013.

Rubio, Marco. “BuzzFeed Brews With Marco Rubio.” Interview by Ben Smith. BuzzFeed. BuzzFeed, Inc, 05 Feb. 2013. Web. 06 Sept. 2013.

Phone interview with William March, 05 Sept 2013.

Reinhard, Beth. “Marco Rubio Accused of Switching Stance on Global Warming.” Colodny, Fass, Talenfeld, Karlinsky, Abate, Webb. Colodny, Fass, Talenfeld, Karlinsky, Abate & Webb, P.A., 11 Dec. 2009. Web. 6 Sept. 2013.

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