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Xavier Duran

Chemist and scientific journalist. Director of the program El Medi Ambient (The Environment) of the Catalan television channel TV3

We listen to scientists when they say what we want to hear

MARCH 28TH, 2011

A few weeks ago at a family meal, a relative told me to be skeptical about climate change. He did not believe, he said, that human activity had anything to do with the increase or decrease in temperature because the Earth's history had always experienced cyclical changes in its climate. There had always been very warm periods and ice ages.

I tried to explain that, regardless of the causes of global warming, the current problem was that the size of the planet’s human population and the complexity of our society make us more vulnerable to certain changes, but also better equipped to monitor or prevent them. Former periods of climate change, leaving aside those that had occurred before human presence, had important consequences for some human populations (see the recent article "2500 Years of European Climate Variability and Human Susceptibility, Ulf Büntgen et al. in Science on February 4, vol. 331, pp. 578-582). Most likely, the consequences of climate change today would be much worse. But, as often happens at family gatherings, a much more mundane topic came up in conversation and climate change was eventually forgotten.

It must be said that my relative is not a scientist and is an average educated person who reads about and stays informed on a variety of subjects. He is not a specialist, but neither is he someone who automatically believes everything he hears. After lunch I thought that if the conversation had continued I would have tried to explain the accumulation of evidence that supports the human impact on climate change and the broad consensus among scientists working in this field (see the article “Policy Makers Are Ignoring Climate Change,” by the ecologist Carles Gràcia). Of course, he could have responded that science, even when there is a broad consensus, can be wrong. But a thought suddenly came to my mind: How did my relative know that the Earth had experienced major changes in its climate in the past, considering that he had not personally lived through any of them?

Our reception of scientific studies

The answer is obvious: he knows the Earth’s climate has gone through major change in the past because he had read or been told so, because numerous scientific studies specify what kind of changes had occurred and at what times. That is to say, he knows this because scientists have proven and explained it. This leads to the following question: why does he accept scientific studies that say climate change is a naturally occurring phenomena and yet reject scientific studies that indicate that human activity plays a role in global warming and warn of its consequences? Why do we trust in certain scientific studies and are skeptical of others?

We pay attention to scientists when what they say is useful or agreeable You could say that this is not unusual. We all quickly accept explanations while immediately putting others in doubt. But in the case of science the dual position is especially interesting because certain scientific explanations_ that in the past there were major changes in the Earth’s climate_ used to cast doubt on what other scientists say_ that present-day climate change is caused primarily by human action and that it can have dire consequences.

This paradox leaves room for an in-depth sociological analysis and there exists extensive literature on the reception of scientific studies or news in general. In his interesting essay Counterknowledge: How We Surrendered to Conspiracy Theories, Quack Medicine, Bogus Science and Fake History, Damian Thompson, a sociologist of religion, presents several interesting examples of and meditates on gullibility in the information avalanche of the Internet age (the book was published in Spanish by Ares y Mares under the title Los nuevos charlatanes).

But I would suggest there is one simple reason: we pay attention to scientists when what they say is useful or agreeable to us. If we are responsible for climate change and its consequences can be dramatic, then we must take drastic measures that will influence our lifestyle. It's more comfortable to think that global warming is entirely natural. And this comfort must be behind what causes us to cite what one scientist says as proof that what another scientist says is false.

There are so many studies it is almost always possible to find one that says we want to hear Apart from the obvious fact that there are studies which vary in their degree of credibility and that there are theories and ideas that require a reasonable waiting period to be confirmed or refuted, many people act this way, basing their beliefs on certain findings while questioning others simply because of one’s bias. It is like the patient that change doctors until he finds one who gives him an acceptable diagnosis.

It also must be said that they are so many studies it is almost always possible to find one that says we want to hear. It is as easy as asking the question a certain way or limiting the source of the data. Therefore, we must know how to read and analyze scientific studies. Of course, this is asking too much of the general public. Everything would improve if people knew more about scientific method, but that is the subject of another article.

Subjects of the article