Opinion, Berkeley Blogs

Trusting your fellow scientist

By Anna Goldstein

In my last post, I told you that Berkeley Physics professor Richard Muller is the go-to guy for proof of anthropogenic* climate change. Maybe that strikes you as odd. Why would I look to a physicist for information about our atmosphere? Shouldnt we be talking with UC Berkeleys Atmospheric Sciences program instead?

Of course, Muller and his team at Berkeley Earth Surface Temperature dont claim to be the first people to measure the change in global temperature over time. When they began that project in 2010, there was an active field of climate scientists claiming that the Earth is warming, and there was also an extremely vocal group of skeptics disagreeing with their results. Muller entered the conversation with the mindset of an impartial third party, someone who could analyze the data without any political or financial incentives often attributed to the climate scientists.

Last fall, Berkeley Earth began to release their preliminaryresultsonline.Their analysis shows that the Earth is indeed warming; in fact, their plot of average annual temperature since 1900 is a nearly perfect match of the previously existing plots. The Berkeley Earth study hasnt converted everyone to a believer yet prominent skeptics likeAnthony Wattscontinue to question the transparency and validity of the studys methods but it has gotten significant attention from Congress and the national media, and the discussion will certainly continue when the results are published in a peer-reviewed journal.

Much of the media attention has focused on whether or not the skeptics will change their minds. But what about the people who championed climate change all along? How have they responded? Are they high-fiving Muller, or are they shrugging, saying We told you so?

Geologist and authorJames Lawrence Powell, in a video for theBig Think series, describes his feelings this way:He should have trusted the other scientists and the peer review process which had produced the data that he was questioning. Two years ago, you had 98% of the climate scientists in the world saying they accepted human-caused global warming. There was no reason to question that data, and it was a little offensive of Muller to simply say, Well I dont believe this until I do it myself.

In an interview with Science magazine, Muller explains why he thought there was in fact a reason to question the data. Yes, many climate change skeptics sound more like conspiracy theorists than scientific critics, but there was also some practical criticism of the existing methods of data collection and analysis, such as measuring temperature in overheated urban areas or combining disparate data sets (see the hockey stick debate, for example). Berkeley Earth, on the other hand, posts all their raw data online, along with detailed explanations of their methodology. Muller was hoping to improve on what had been done before, not just repeat it for the sake of seeing it with his own eyes.

Whether or not you were offended by Mullers attempt to calm the climate change debate, Id like to focus instead on Powells deeper message. He claims that scientists have a responsibility to trust each other. As he says in the video, If every scientist said, Im not going to believe what anybody else did until I do it myself, scientists would be at least a century behind where we are right now. That is, if something is done by a reliable lab, passes peer review, you should at least tentatively accept it until somebody shows you some reason why its wrong.

This is a bold statement, and it made me think. As scientists, skepticism is one of our main responsibilities, maybe even our first priority, because we have implicitly agreed to collect knowledge from the physical world rather than myth or superstition. We must beskeptical of claims, unless they are supported by empirical evidence. So how did we end up with a scientists vs. skeptics debate, where scientists are compelled to say dont worry, just trust me?

From what I can tell, Powell is not actually calling for a new age of non-skeptical scientists; his argument boils down to efficiency. With the immense volume of data being collected reported on a daily basis, it is in everyones interest to give scientists the benefit of the doubt, to assume that they are performing their work competently. And this is exactly what happens, in almost every sub-field of science. We allow the members of eachcommunity to check each others work, and then we trust their consensus. Something that is considered established fact by geologists is then accepted by chemists, astronomers, geneticists, and everyone else, including politicians.

It is only in certain special cases (climate change, evolution, vaccines, etc.) where cultural opinion butts up against scientific fact, that we have skeptics questioning skeptics, and everyone is scrambling to prove that the truth is on their side. Unfortunately, in the case of climate change, the policies made by todays governments may be a matter of life and death, for humans and most other species on our planet (cockroaches and extremophiles not included).

So in the end, I think Powell should go easy on Muller and his team. They saw a messy debate (replete with scandals, basically a P.R. nightmare for science), and they decided to enter the fray, but their contribution has been based on calm, rational discourse. They certainly deserve a high-five for that.

*Muller's claims are actually limited to measuring global warming, rather than identifying its cause. He says that there is still uncertainty regarding how much warming is from human activity. Thanks to commenter Rachel for the correction.

Further reading

NYTimes: Climate Study Does Not Placate Skeptics

Science: Q&A with Richard Muller

Cross-posted from theBerkeley Science Review,a graduate-student magazine on research occurring at UC Berkeley.