Richard Muller shows what it means to be a climate change skeptic

We interrupt your weekend with MAJOR SCIENCE/POLITICAL NEWS. As the headline of this ThinkProgress blog entry notes, this is indeed a political bombshell. MacArthur “genius” grantee Richard Muller, a highly respected physicist and self-declared climate change skeptic has changed his mind in precisely the way a scientist should: He examined the evidence.

As far as the science goes, this is nothing new. Nor is Muller’s conversion from climate skeptic a total surprise. A few months ago, he announced that his research had convinced him that global warming is happening, but his work had not determined whether human activity was to blame. Now, based on further research by his Berkeley Earth project, he has gone further, stating that he supports the broad consensus view that human activity is to blame. He writes this in a New York Times Op-Ed article:

Call me a converted skeptic. Three years ago I identified problems in previous climate studies that, in my mind, threw doubt on the very existence of global warming. Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. I’m now going a step further: Humans are almost entirely the cause.

My total turnaround, in such a short time, is the result of careful and objective analysis…. Our results show that the average temperature of the earth’s land has risen by two and a half degrees Fahrenheit over the past 250 years, including an increase of one and a half degrees over the most recent 50 years. Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases.

Skepticism becomes denial when you ignore the evidence. Muller was a strong skeptic of anthropogenic (human caused) global warming, but he was never a denialist. Now that he has been able to examine the evidence thoroughly, he supports the consensus view. In fact, he notes that his group’s findings go beyond those of the consensus view as stated in the 2007 report of the Intergovernmental Panel on Climate Change.

What makes this even more remarkable is that his research was funded by the Koch Foundation, whose fossil-fuel billionaire benefactors, brothers Charles and David Koch, have been arguing against the consensus for years with little evidence and lots of bluster.

So on this issue, Dr. Muller has become a strong supporter of the consensus view. But if you take the time to read his New York Times article, you will see that he has not surrendered his scientific skepticism. Like a good scientist should, he challenges predictions that he calls “alarmist.” He doesn’t rule those out entirely, but he needs to see more evidence before accepting them.

He closes the article by removing his scientist hat and donning his citizen’s one: “I hope that the Berkeley Earth analysis will help settle the scientific debate regarding global warming and its human causes. Then comes the difficult part: agreeing across the political and diplomatic spectrum about what can and should be done.”

As anyone who has observed the US political scene in recent years knows, agreement will be hard to find. Perhaps politicians can learn something from scientists in framing their arguments: policies need to be developed by looking at the evidence with a skeptical but open mind.

18 thoughts on “Richard Muller shows what it means to be a climate change skeptic”

  1. If we are experiencing global warming how can we know from a few years of data if this is a trend or a statistical aberration? In geologic time even a few thousand years is but a tiny sample size from which to draw a conclusion much less 50 years.


    • Benjamin, that’s an excellent question that is addressed in many places. I don’t know your scientific background, so let me suggest several ways to go further.

      For a reading list for non-experts from the past 15 years that approaches climate change from many perspectives, look at the weather and climate book reviews at my Science Shelf archive.

      Then there is the analysis of Dr. Muller’s Berkeley Earth project.

      If you are up to a lot of scientific data and analysis, you can read the 2007 report of the Intergovernmental Panel on Climat Change.

      But there are also a few simple back-of-the-envelope calculations that can show how unlikely the recent climate has been. For instance, nine of the hottest ten years on record have occurred since 2000. Muller’s work validates the data, even though he started out doubting that the measurements were valid. What are the odds that that occurred at random?

      Every claim the skeptics put forth has not held up in light of analysis like that of Muller or the IPCC. You will continue to see claims in the media that there is some kind of conspiracy or scientific misconduct, but that, too, has been investigated and found lacking.

      This just scratches the surface of the huge body of evidence supporting the consensus. The fact that a distinguished and highly respected skeptic has now gone on record in support of the consensus view is very important. I hope this helps you get started if you want to look into that body of evidence for yourself.

  2. It seems like there’s one question left unanswered: were the world’s climatologists too quick to jump to a conclusion, or was Richard Muller being too skeptical (or too little informed in the first place to have warranted a strong opinion)?

    • Joseph, I don’t think it is either/or. Scientists are always open to new evidence. Muller is known for his unique viewpoints, and he thought he saw problems with methodology. So he got funding to test his conjecture, and ended up confirming the consensus instead.

      The consensus is stronger with each challenge met, and the bar is then set higher for new challenges. That’s the way science is supposed to work.

  3. Dear Fred,

    Skepticism is of course an essential part of the process. But if we were all to employ the same philosophy as Dr. Muller which amounts to “It’s not true unless I do the research myself” the human race would a) agree on very little and b) achieve progress at a snail’s pace. The ultimate skeptical position may, perhaps, be one for the philosophical purist but for those of us of a more practical nature it will not suffice.

    I also think that it’s no bad thing when he challenges the future predictions. This is how science improves. However, as documented by skeptical science his challenges, from the NY times article at least, are based on distortions or falsities. Until he can generate some objections based on science these cannot be taken credibly.

    (Reposted from my blog)

    • Dear Cameron,

      Thank you for your comment.

      I’m not saying that everyone should do the research, but when you have Mueller’s stature as a Macarthur Genius and best-selling author and both the inclination and means to look at the data from a different perspective, then by all means, do the research and publish your findings.

      • Hi Fred,

        That’s a fair point but after reading the rebuttals by skeptical science do you really think Muller has been entirely honest throughout this story?

        Best wishes,

        • From my personal long-distance interactions with Muller and especially with Frank Asaro, who introduced me to Muller while I was working on To the Young Scientist: Reflections on Doing and Living Science, I don’t think he has had any reason to be dishonest here.

          His scientific history is one in which novel ideas have always appealed (see his book Nemesis: The Death Star), and he enjoys holding people’s feet to the fire to make sure they get it right.

          He’s still doing that as far as some of the scenarios about our climate future. He isn’t saying that the scenarios are wrong. He’s just saying that he is not yet persuaded. But to his credit, he is also advocating political action to reduce CO2 that goes far beyond what our government has been able to do.

          At Skeptical Science, what you are hearing is the people whose feet are being held to the fire saying “Ouch!” They are defending their scientific position, which is indeed a strong one, and their defense advances the science. But attacking Muller’s motivations, as some of them are doing, does not advance the science in any way.

          My two cents worth.

          • You make a fair point about skeptical science, but given that Muller’s research was funded by the Koch Brothers one has to ask, why? Given the recent news about them funding many organizations that are unscientific, to put it politely, we have to question why they would want to fund Muller’s research. I think it is too easy to say that Muller is simply acting as a good scientist. He could well be, but the story behind this hints at something else.

  4. Cameron,

    My approach is simply this. Why invoke a conspiracy theory when a less complicated explanation is available? Muller was skeptical and he took money from people who wanted him to pursue his questions. He followed the evidence, produced firm conclusions, and laid out his findings even though they went against his funders’ prejudice.

    Note that the conspiracy theorists are usually on the other side of this argument, and they have accused legitimate scientists of being guided by dollars and politics instead drawing their conclusions from overwhelming evidence. Did you give conspiracy theorists any credence when they made such arguments? Clearly not. So why are you now talking about “hints at something else” in regard to Muller?

    I’ll stick to the science and leave out the tabloid-style gossip and personal attacks on both sides.

    I guess there’s nothing further to say on this. We need to put our energies into promoting good science and good policy based on those results.

    • Hi Fred,

      You’re right, the other side has normally been involved in conspiracy theory style attacks. But I didn’t use that word here, even if it may appear what I hint at. I simply ask why the Koch Brothers have funded Müller’s research given recent news* (e.g.

      Is that not a legitimate question? Would you trust the motives, or the freedom, of researchers who took money from tobacco companies?

      Muller has found that warming exists and is probably caused by humans but he continues to peddle the dangerous message that it’s nothing to worry about. A message that would certainly serve the Koch’s aims.

      Unfortunately we cannot detach science from the human situation as it stands.

      I’ll say no more and perhaps we’ll just have to agree to disagree.


      *this is in contrast to my original blog article, which is admittedly quite of a conspiracy theorist angle. Rather than criticise Muller as I did then, I would now rather pose some questions which perhaps one day himself, the Kochs or someone else will be able to answer.

      • You raise an interesting question, Cameron. It’s one where neither of us has a clear answer, I suspect. I’d welcome your thoughts about it.

        The Koch funding for climate change denial is no surprise, though, as that article points out, it is more extensive than most of us thought. (The article isn’t news to me, and I concur in recommending it.) So the question is, should a reputable scientist–indeed, a Macarthur Foundation Genius grantee–accept funding from someone with a political agenda? That includes not only the Koch Brothers but also environmental organizations that have been engaging in political action to persuade people of the need to act on greenhouse gas emissions.

        Muller did so, but he insisted on a no-strings attached policy. And he used that funding to produce results that ended up undermining the Koch brothers’ agenda. They may be using his conclusions to say, “See, we’re not that bad,” but no one really believes that rationalization, especially since Muller is now on the receiving end of their accusations. Muller’s New York Times Op-Ed has been and will continue to be a strong counterweight to Koch-ic climate lies and deceptions.

        During the heyday of the tobacco disinformation campaign, there were no scientists who took big tobacco money without strings, and as a result, there was no one with such stature to say, “The evidence has persuaded me to change my mind.” Had there been such a scientist, perhaps the country would have moved faster to limit tobacco advertising, etc.

        It’s impossible for me to put myself in Muller’s shoes to answer whether I would take Koch agenda-tainted money. I probably couldn’t, but nevertheless, I like the outcome that resulted from Muller’s choice to do so.

        Your thoughts?


        • Hi Fred,

          You make a very good point about what happened during the tobacco days. It’s given me some cause to reconsider my stance. However, given the inconsistencies in his NY Times article, it’s still hard to swallow. As ever with climate change, we’ll find out in the future whether Muller was correct or not.

          Best wishes,

          • I’ll wrap this up with sincere thanks to Cameron, who notes, “As ever with climate change, we’ll find out in the future whether Muller was correct or not.”

            I’ll add this note of agreement. Like Cameron, I think Muller’s remaining points of skepticism are likely to prove as unfounded as his earlier ones. The climate modelers’ scenarios seem very persuasive to me and the evidence already seems to be answering Muller’s challenges.

            Still, nothing gives a theory staying power more than a demonstration that it can survive a challenge from a well-informed critic. It’s hard on the personal level to be on the receiving end of a sharp critique, but on the scientific level, the best answer to the critic is often in supporting evidence that comes as a result of the challenge.

  5. I noted in the main article that “Like a good scientist should, [Muller] challenges predictions that he calls ‘alarmist.’ He doesn’t rule those out entirely, but he needs to see more evidence before accepting them.”

    In an unfortunate follow up op-ed called “The truth about tornadoes,” Muller takes on the science of tornadoes without fully researching it.

    According to a sextet tornado experts, he is simply wrong in his conclusion that the number of tornadoes is decreasing.

    In their blog article called “The Real Truth About Tornadoes”, they conclude:
    “…Muller’s simple analysis of tornado reports does not address possible changes in the seasonality and/or regional nature of tornado occurrence. In fact, the latest climate-model experiments agree that further global warming is likely to increase the likelihood of conditions favorable to the severe thunderstorms that produce tornadoes in the spring and autumn. Although these climate models do not resolve tornadoes, they do predict an increase in the ingredients responsible for past tornadoes.”

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