Scientific Consensus is Not an Argument from Popularity

There are a great number of us in the general public who are not scientists and yet science news surrounds us.  It can be hard for those of us with an expertise of near zero in science to determine what constitutes sound science. In the current media environment where anyone with internet access can have a blog or upload a video, it can be even harder. Some of these people may be sincere but misguided while others might have more nefarious intentions. Working for some special interest, they may seek to blur the science landscape, littering it with a little truth, a little misrepresentation, a little skewed graphic.

In some cases, there is real science being hyped by the news for clicks and pageviews in order gain income. It is a sad state of the media that popularity drives the news: papers need to get readers and to attract readers, they resort to hyperbolic headlines.

The thing is, popularity does not drive science. Science is not "true" based on how many people believe a certain claim. But there is a way to establish if a scientific theory or claim is most likely true, and that is consensus. Consensus is not the same as popularity. When we say that most scientists accept a theory, like evolution or climate change, what we are saying is those with the most expertise to evaluate the claims have examined the data, have reviewed the claims, have done or redone the experiments and have published their findings in journals in which others with the same or similar expertise evaluate their claims. It matters little if a meteorologist or a chemist "don't believe" climate science. They are not the experts who have done the research.

This is a significant difference between popularity and consensus. Popularity can refer to the number of people who believe, buy into, accept something, or how many of them consume a product or like something. In many areas, like which candy bar is best, popularity is just fine. Anyone can have an opinion on food. But in science, what matters is do those with the most expertise to evaluate accept something as likely true. How I feel about evolution matters nothing. It is how qualified a person is to weigh the evidence and analysis.

In the case of climate science, the number that gets batted around is 97%. That is, 97% of scientists agree it is happening. Now, this wasn't just some poll that an agency conducted. There have been published studies in which the author looked at articles on climate. Here is one. It is important to note that the number is reached by looking at those with the most expertise (climate scientists) publishing their findings. And it is not simply that scientists "opinion." It is examining the findings of his or her research.

Looking at a single study or reading the work of one researcher may not be the right way to go about understanding what is most likely true. Sure, one person may indeed have the right model for what is going on, but humans can make mistakes. They can be biased. Even those with excellent training to remove factors that interfere with perceiving reality.

And the reality is, there is in all likelihood something out there we call reality that we perceive only imperfectly. We are looking for instruments and mechanisms to find out what is out there. People complain that "science changes," but what they don't understand is that it is our understanding that is changing. The world - the universe is out there, doing its thing. We don't comprehend all the mechanisms.

Some people like to put a lot of stock in "just knowing," that is, knowing before there is evidence to know. Sure, it's fun to have an intuition proved right. The fact is, though, our intuition is often wrong.

Let's think about a Biblical view of the age of the universe. Isn't it satisfying to sit back with a smile and just know it's 5-10k years old? No need to question anything. And that age was fine for bronze age people wandering the Middle East. What could they know? As we developed instruments, though, we could see further. I have heard creationists laugh at how the age of the earth has changed in the past 200 years. They smirk and smugly state that science is silly for not knowing. But we can only know as far as we can see. Our understanding changed when we could see our solar system, then our galaxy then further and further into the universe.

But we don't believe in the findings of science the way people believe in religion. We examine, we ponder, we measure, we weigh, we consult with experts. None of it is true because Charles Darwin said it. None of it is true because scientists "like" it. It is likely true because that is the way the evidence points, and those with the ability to understand the evidence work together to establish what that means.