Rush Limbaugh grossly distorted a new study from Duke University, claiming it shows that “there isn't any [global] warming going on.” But one of its authors noted that the study actually confirms humans' role in driving global warming and said that Limbaugh's claim is “ridiculous.” 

On the April 22 edition of his show, Limbaugh touted the Duke University study as "[b]ad news for the climate change crowd" and claimed the Duke researchers are part of a “consensus” of people who think “there isn't any warming going on.” He went on to assert that the study, which examines temperature records over the past 1,000 years, shows that “there's no evidence whatsoever to suggest that long-term warming over the next 100 years is going to be anything even noticeable, abnormal.”

But the study itself said nothing of the sort. Rather, the study stated that, out of the range of warming projections outlined by the United Nations' Intergovernmental Panel on Climate Change (IPCC), temperature records suggest that at present time the “middle-of-the-road warming scenario” is more likely than the most severe warming projections. One of the study's authors, Duke doctoral candidate Patrick Brown, confirmed as much in an email to Media Matters, and called Limbaugh's assertion “ridiculous”:

The idea that there 'isn't any warming' is ridiculous. Over the past century there are countless datasets indicating warming (weather stations, sea level, ice mass, ocean temperatures, etc.).

[...]

Our study shows that we are probably not on the worst-case IPCC scenario but that we may be on an IPCC middle-of-the road scenario. The IPCC does not make predictions they make hypothetical projections. So this result does not contradict the IPCC conclusions at all.

The study also stated that natural variability “can slow or speed the rate of warming from decade to decade,” and cited this as a reason not to be over-reliant on “short-term temperature trends.”

Limbaugh claimed this meant the study was saying that “the sun” could be responsible for recent global warming. But the vast majority of scientists would say otherwise. Indeed, Brown explained to Media Matters that Limbaugh is “wrong” to attribute recent warming to solar activity, and added that human activity is a much bigger contributor to warming in the past century than natural variation:

[O]ur study confirms that the warming of the past century could not have happened without human-caused increases in greenhouse gasses. This is because the warming over the past century is much larger than what could have come about due to natural variation.

[...]

Rush is wrong in his interpretation. The solar contribution to recent temperature change is probably minimal and/or negative (i.e., the sun has probably caused cooling, but human increases in greenhouse gasses have overwhelmed that small cooling to cause a net warming).

Science writer Greg Laden wrote that the Duke study will receive “criticism from climate scientists” because it includes language that suggests it is assessing the likelihood of different warming scenarios by predicting the amount of greenhouse gas emissions that will occur in the future, which it can't possibly know. However, Laden noted the study doesn't actually “say that one or another scenario is likely or less likely” and “says nothing about the validity of climate models.” Rather, according to Laden, the Duke researchers “have provided an insight, if their work holds up, on how random wanderings of reality from projections, in both directions (cooler than expected, warmer than expected) will emerge depending on what we do with our greenhouse gases.”

Laden concluded that the study's findings do not provide a “change in how we think about global warming,” but rather a “refinement.” But he warned that the results are likely to be “abused by denialists” and are being misrepresented, “willfully or through misunderstanding, by climate science contrarians.” Limbaugh is a case in point in this regard.

Limbaugh, who frequently attempts to deny climate change, concluded his segment by claiming that he was helping Brown get his message out: “We've gotten your message out for 25 years, the message that there isn't any warming, and there isn't in the specifically past 18 years. There isn't any, and we've gotten that message out.”

Limbaugh may have been spreading the same message for the last 25 years, but it's clearly not the message of Patrick Brown -- or the rest of the 97 percent of scientists who agree on man-made climate change.