I had gone into the world's biggest annual skeptics' gathering hoping to be disillusioned. I'm not one given to paranormal or religious beliefs, but I thought after being exposed for four days to hundreds of members of the international skeptics' community, I might expect to leave cleansed of at least one or two erroneous or irrational ideas. I was to get my wish, but not the way I'd expected.

The meeting, which took place in a Las Vegas casino in July, was called The Amazing Meeting, or TAM for short. The star of the show is James "The Amazing" Randi, a magician and investigator of claims. The meeting functions as a fundraiser for his James Randi Educational Foundation, whose mission is "to promote critical thinking by reaching out to the public and media with reliable information about paranormal and supernatural ideas so widespread in our society today."

Randi became well known to scientists and those of us who cover them back in 1988, when he joined a team investigating a French immunologists' unlikely claim that water could "remember" antibodies that had been diluted to zero concentration. The original finding had become a scientific scandal for getting into the prestigious journal Nature and for seeming to back the discredited mechanism behind the discredited field of homeopathy.

The magician and his fellow investigators showed that when the French researcher was blind to which samples once contained the antibody, the weird memory effect went away. The scientific community was grateful for having the record set straight and for the valuable insight into how the experiment went wrong.

This year, TAM drew 1100 people from as far as Bangladesh and Australia – many of them staying up until the wee hours in the casino's lounge to interact with like-minded people and rub shoulders with certain celebrity skeptics. The theme this year, Fighting the Fakers, seemed to encapsulate what organized skepticism could do for the rest of society.

The four day meeting included dozens of 30 minute talks – I volunteered to give one on skepticism in the media. I listened to most of the other talks, though it turned out I already disbelieved all of the claims being discussed: Exorcism, alien visitations, psychics, variations on faith healing, "cold reading" - a form of mind reading, ill-informed chemical phobias.

Many of the talks weren't aimed at debunking anything – a sex therapist talked about "moral panic" on the part of the religious right as a reaction to increasing sexual freedom. One speaker talked about a website that casts doubt insufficiently skeptical news stories – mostly material from gossipy tabloids and websites known more for quantity than quality. Someone talked about giving up the Mormon faith. Another, on how actors and other creative people were not really fakers – they were "honest liars".

One talk that surprised me was a sort of climate science 101 briefing from Michael Mann, the Penn State scientist who is known for the so-called hockey stick graph reconstructing the last few centuries of atmospheric composition and global climate. He's also one of the victims of "climategate" - a hacking incident in which his emails were stolen and touted as evidence of fraud. There was no evidence and he was cleared.

I wrote a lot about Michael Mann when I covered science for The Philadelphia Inquirer. Why was he talking to the skeptics now and not back in 2009, when he was being accused of fraud by alleged "skeptics"? I reasoned that he certainly could have used the support of authentic skeptics while being attacked by fake ones.


It wasn't until after I got home that the skeptics disillusioned me. I started poking around, curious about the relationship between climate scientists and the skeptics' community when I came across a 2009 piece by Randi himself, called AGW revisited, AGW referring to anthropogenic global warming. The bottom line – Randi wasn't convinced.

Now the disillusionment wasn't about climate change. There's an overwhelming confluence of evidence coming from earth and planetary science, physics and chemistry showing that human activity has changed the atmosphere enough to disrupt the climate. Undergraduates can work out the physics of greenhouse gases and how they hold heat in the atmosphere. There are solid measurements showing just how much we've added in the last century.

The shocking aspect of Randi's AGW piece wasn't the subject matter – it was the approach. It wasn't very reasoned nor was it skeptical. Much of it could have been cribbed from creationist propaganda.
There was something I found unfair about Randi's use of the term "AGW" which he never clearly defined, thus allowing him to poke holes at a non-existent viewpoint in which all observed climate change is 100% caused my human activity. Then there was the suggestion that scientists can't be trusted:


"......An unfortunate fact is that scientists are just as human as the rest of us, in that they are strongly influenced by the need to be accepted, to kowtow to peer opinion, and to "belong" in the scientific community.....academics [are] often more driven by "politically correct" survival principles than by those given them by Galileo, Newton, Einstein, and Bohr.....Religious and other emotional convictions drive scientists, despite what they may think their motivations are."


Creationists make similar statements to try to discredit biologists.

Then Randi demeaned the power of scientific consensus, much the same way peddlers of fringe claims and pseudoscience do to imply that being rejected by the mainstream is actually a good thing.
There was reference to a petition:

"...some 32,000 scientists, 9,000 of them PhDs, have signed The Petition Project statement proclaiming that Man is not necessarily the chief cause of warming, that the phenomenon may not exist at all, and that, in any case, warming would not be disastrous."

The phrasing here suggests readers should be impressed by the small minority of these scientists who had PhDs. Creations have floated similar petitions to make it seem the scientific tide is turning against evolution, and the term scientist is similarly very loosely applied.

Randi wrote a follow-up, I am not Denying Anything, in which he backed away somewhat, but did not retract or apologize for the original piece. He acknowledged that he knew little about climate science. In this case he may have known so little that he confused basic science with an extraordinary claim.


Carl Sagan famously quipped that extraordinary claims require extraordinary evidence – but what, exactly, makes a claim extraordinary? To scientists, extraordinary claims are those that, if true, would violate decades of established science. Homeopathy, for example, would violate just about everything scientists have learned about water since they realized it was composed of H2O molecules. Many alternative medical ideas similarly rely on energy fields whose existence would have to rewrite decades' worth of basic physics.

In the case of climate change, basic science is on the side of the mainstream view. The extraordinary claim is coming from those who say there's no connection between carbon dioxide and climate or that nearly doubling our atmosphere's CO2 is unlikely to have an impact, now or in the near future.

The science goes all the way back to the 1850s, when French mathematician Joseph Fourier realized that at 93 million miles from the sun, the Earth should be frozen. He reasoned that our atmosphere may do something to keep us warm. His idea was confirmed by the experiments of English physicist John Tyndall. He shone light through various gases, showing that it passed through oxygen and nitrogen, but was absorbed and re-radiated by carbon dioxide. And by the early 20th century, scientists started to consider how all the CO2 released from burning coal might change the climate of the future.

Today, scientists aren't claiming that every heat wave or drought or tornado is directly caused by human activity. But many are concerned that human activity is influencing the climate, and will continue to do so in ways that are hard to predict and likely to disrupt agriculture and other aspects of human life.


Randi's piece on climate change made much of the fact that the greenhouse effect "as applied to our planet" is complicated. The most damning part, however, was an anecdote about a pseudoscientist of some kind – as if this was relevant to climatology:

"My most excellent friend Martin Gardner once asked a parapsychologist just what sort of evidence would convince him he had erred in coming to a certain conclusion. The parascientist replied that he could not imagine any such situation, thus -- in my opinion -- removing him from the ranks of the scientific discipline rather decidedly."


This passage may reveal a lack of understanding of the nature of evidence in earth and planetary science – something that can't always be replicated in a test tube. During the late 20th century, planetary scientists realized that if their understanding of the greenhouse warming is correct and could be applied to anything as complex as a real planetary atmosphere, they should be able to take the atmospheric composition of other planets measured with remote sensing, and use it to predict the temperatures spacecraft would measure directly. If they didn't match up, that would give them serious reason to go back to the drawing board.
Their calculations matched the measurements.


Other tests looked not outward but back in time. Did past fluctuations in atmospheric carbon dioxide have any relationship to global temperature? It's not an easy question to answer, but by drilling more than two miles into Greenland and Antarctica, researchers have pulled up ice cores that hold more than 110,000 years' worth of atmospheric and climate history.

Some paleontologists look further back still, connecting CO2 increases from volcanoes with dramatic periods of global warming and mass extinctions.

The skeptics listened intently as Mann sorted out what was basic science and what was still up for debate. Climate science is complex and full of uncertainties but as Mann explained, they acknowledge those uncertainties and quantify them with error bars. Just because Earth's climate is complex doesn't mean it can't be approached by science – what is our alternative?

After four days among them, I knew skeptics are a diverse lot and hold many different positions on climate change – most of them quite sensible and scientifically based. But I was no longer under the naïve illusion that there was some wall separating the good skeptics from the crank "skeptics" who have made unreasoned attacks on climate science and the people who practice it (as well as those of us who cover it). Just like most other human endeavors, skepticism can be done well or badly.

I wondered if the skeptics' community could benefit from adopting one of those values espoused by journalists – fairness. That does not mean presenting all sides, no matter how nutty, as if they are equal. It means accurately portraying the nature of claims, being specific, and refraining from cowardly use of innuendo. It's not fair to tell a story about some fraud claiming paranormal powers, for instance, as if this illustrates anything about Michael Mann and his colleagues.

There is nothing wrong with skeptics deciding to cast a critical gaze at climate science or any other area of research. Sex, religion, politics and climate science may make uncomfortable dinner party conversation but they are all fine topics for scientists or journalists or skeptics to investigate. Had Randi conducted a fair and reasonable investigation, he might very well have come out in the same place as the scientific community.