Evolution, climate change, and uncertainty: why understanding the process of science matters

As the National Center For Science Education has been demonstrating for some time now, denying biological evolution and denying climate change are part of a larger phenomenon related to science illiteracy.   But I think we often tend to conflate the knowing of scientific data with knowing the process of science itself.  As a college professor, I can tell you that  smart students who know a lot about the natural world don’t always actually know the process of science.  In one of my first lectures to undergraduates in the introductory biology majors course, when I press them to define science, hypothesis, and so on, very few can.  And I have come to believe that our current societal issue with accepting science is a fundamental misunderstanding of the process, not simply a dearth of facts.

In my undergraduate days, I was a climate change denier.  That’s correct — I felt that the evidence was at best equivocal for global warming.  If you couldn’t prove it directly, how confident could we be?  In fact, I felt a good amount of the environmental “science” out there was nothing more than misplaced hysteria or political propaganda. For those who do know me and my political leanings, you are probably surprised.

So I speak from experience when I say that I understand the reservations among many people when it comes to climate change.  Ask any climate scientist, and they will never tell you with 100% certainty that their predictions will come to pass.  In fact, these scientists rely on models of climate, and those models are a hypothesis of reality, not reality itself.  Remember, I was a science major with aspirations of becoming a paleontologist, so my undergraduate self decided that if we couldn’t be certain, we shouldn’t go around broadcasting that it was the end of the world.  In my undergraduate head, the best science was certain, and that was why paleontology was so difficult — a lot of uncertainty.

So here’s the thing — a climate scientist can show you a lot of data (see below), and can tell you based on their expertise which are the most probable outcomes of current trends, but if you were my undergraduate self, you would not be convinced.

From Wikipedia Commons: “This image is a comparison of 10 different published reconstructions of mean temperature changes during the 2nd millennium.”

Whether or not my younger self (let alone my older self) was stubborn or simply a bit daft (probably both), I again point out a key feature in the thought process: if it isn’t certain, it’s not good science.

So, the assumption or implication that good science is certain is the first part of the puzzle.  The second part of the stubbornness by many of us to accept climate change or perhaps biological evolution is that we want evidence presented in a court room.  We want the TV show Law & Order, and we want the good lawyer to give us an iron-clad argument, or to show that our opponent is a lesser person, or to literally give us a smoking gun.  We are convinced that science works like this, and that the person with the best argument and evidence wins.  And most importantly, that the winner stays the winner.  Nothing can ever overturn the win.  Good science should be certain and win the day’s argument, for now and forever.

But of course, science has little or nothing to do with certainty and court room drama.  There is no certainty in science — there is simply probability.  Because a good scientist recognizes that we are only human, and we can only realistically deal in samples, we can’t measure every aspect of the known universe, and we certainly can’t have all the data on all the clouds, carbon dioxide, and local temperatures.  Therefore, a good scientist will never say they have “proved” something — rather, they will indicate that their data suggest certain scenarios are more probable than others.  The higher the probability, the more confident one can be that the predictions may come to pass.

It took a while for this concept to sink in with me.  It took graduate school and having to do science, and taking an excellent seminar from Professor Emeritus Ronald Toth at Northern Illinois University, that finally made science as a process click.

(As an important aside, much of my thinking as a scientist I owe to Ron — so the “smart” stuff I say about evolution and science are me emulating him.  My evolution podcasts and understanding evolution website are extensions [and I hope a sincere form of flattery] of Ron’s approach.  Thank you, Ron!)

That means, as someone who earned a B.S. in Geology with a Biology major, I had no real concrete idea about science as a process!  I am not surprised nor judgmental that many of our undergraduates, let alone the larger public, don’t understand this either — but this I believe is what needs to be most addressed.

Even if you do succeed in uncovering something new or accurately predicting a trend, there will always be new data. The complaint you often hear about science is how we keep changing our damn minds — we knew Pluto was a planet, or we knew that birds were not dinosaurs, or we knew that cholesterol was bad, and so on. But the process of science requires that one keep testing the hypothesis, and to incorporate new data as it comes in.  So we’re not changing our minds to tick you off — we adapting our models and our understanding of the natural world as more data come rolling in.

What I realized at long last in graduate school was that scientists speak in probabilities.  And when you think about it, we deal in probabilities all the time, and we make decisions based on those probabilities, and we are okay with that.  Every time you get in a car, there is a probability you will be in an accident … but you probably still get in that car.  Imagine if someone told you that unless you could 100% guarantee that no accidents would ever occur, it was pointless to drive.

Okay, but now for something more ominous: what about the probability that you will get sick if you ingest salmonella bacteria.  I have been sickened myself by this nasty “bug,” and many people have died from salmonella poisoning.  But there will always be cases where someone ingests salmonella or another pathogen and doesn’t become sick.  Now imagine a friend tells you that since every time a person has ingested salmonella they haven’t always become ill or died, we don’t have enough data to know whether or not it is truly deadly.  Therefore, wasting money and resources on preventing the spread of salmonella is not advisable because we can’t know with 100% certainty that everyone who ingests it will get sick or die.  This person would probably not remain your friend for long.

Probability in science works along this spectrum — from low to high odds.  Low odds: you will be hit in the head and killed by a rouge meteorite tomorrow.  High odds: the climate will continue to change, with an overall trend toward higher global temperatures.  Can we be certain climate will change in these ways?  Not 100%.  But the probabilities are high … and that’s why we should be concerned: the scientific predictions of increasing global temperatures suggest our world will change in ways that, if we are not prepared, will be devastating.  Of course, we could wait until we’re certain, and we could wait for the ultimate court room battle of the sciences … but if the probabilities are high, why wait?  What are waiting for?  Waiting for all the data to come in (which will never happen) and waiting for 100% certainty (which will never happen) is simply another way of doing nothing in the face of probable danger.

If you understand that the process of science is by its very nature is one based on probability, not certainty, I think we begin to get to the heart of the scientific illiteracy problem.  Giving people more and more data won’t help if they sincerely believe that uncertainty means no one knows anything.  This is, I believe, the core issue with science literacy — and why our politicians, our media, and our public are so often mislead to disregard good science and its important predictions that effect us all.


25 thoughts on “Evolution, climate change, and uncertainty: why understanding the process of science matters

  1. Great piece. Unfortunately, good science is never good enough for many folks. Even if the probabilities are high, little or no action will probably be done at the present because the people who will directly wrangle with the full force of climate change are still in diapers—or perhaps yet to be born.

    • Hi Oliver,

      Yes — the pace of change often moves slowly. I think we are all guilty of not acting on something until the problem becomes unavoidable and undeniable. I have children, so I still hold out hope for our future!

  2. I loved this piece and hope it’s not a problem for me to open a discussion in the intro. biol. course I teach with it (if so, please let me know!). I would add on thought to it – that failure to act, even with high odds of great danger (in communication theory, this is about acceptance of risk), is an innately human behavioral trait. We tend to avoid action, even when that action would be greatly beneficial to us, if it means the action will cause short-term pain (even just the pain of inconvenience). So we avoid opening the bill we don’t want to see, avoid going to the mechanic when the check engine light has been on for a month, avoid seeing the doctor about the lump, avoid changing lighting to energy-efficient bulbs, etc. We really dislike changing how we’ve ‘always done things,’ even when we know that we will greatly benefit by that change.

  3. I understand what you are saying. But when I go back to climate records that I compiled by hand 35 to 40 years ago from official weather stations and find that the data from the same time period of those same stations consistently show warmer temps than what I copied from those records years ago . . . smells very fishy.

    • Hi Dana — I am certainly not a climate scientist. However, my question for you would be, how was your data collected and does that data collection compare with how the other studies collected theirs? Are we perhaps comparing apples and oranges here? And were the climate records local or global? What was measured? What I find convincing is that multiple studies from different teams of scientists keep converging on the prediction of a warming global climate — typically, when I see data consilience, I gain more confidence in the predictions. Were it simply one study or even a handful that showed significant warming, but an equal or greater number that did not, I think many of us would be less convinced. Instead, the majority of trends keep pointing like an arrow at increasing global temperatures.

  4. I agree completely with your reasoning. I teach Earth Science (I have a BS in Geology) and it wasn’t really until I started teaching science that I fully understood science. I’m doing my best presenting this information to my high school students and I hope my enthusiasm for it rubs off on them.

  5. Yet in all other aspects humans make uncertain and often risky decisions: relationships, careers, holidays, gambling. I think vested interests combined with a general reluctance to confront unpleasant realities are the real reasons that climate change deniers are able to have any impact. Perhaps if we used an environmental context ie. not trashing the planet’s environment the scientific message would be more successful.

    • Hi Judy — you make a fair point … I think coupling emotional motivation with improved communication on how science works is a key way to get action on a significant event that is already having an effect on our lives.

  6. Since you gave permission I plan to use your letter in my introduction unit Scientific Thinking with my freshmen biology students. One of their first assignments is to gather data and site their resources on the topic of global climate change. After they turn in those reports we will be reading your blog. Then we will have a class discussion. This won’t happen until next week but i will let you know how it goes.

  7. You should take a look at the following journals in science Ed: Journal of Research in Science Teaching, Science Education, Journal of College Science Teaching. Unfortunately, the results are bleak- an understanding of the nature of science, by itself, does not guarantee an individual will be scientifically literate, at least as defined in the science education community.

    • Hi Steve — yes, agreed: all things in isolation generally do not translate into workable knowledge, let alone an appropriate understanding. From my experience in the college classroom, I think showing how the scientific method applies to different situations and how it helps us make reliable predictions are key. Simply telling students how science works without the opportunity to do it themselves, or to at least participate actively in constructing a hypothesis or testing a prediction, won’t get us very far. Still, I suggest that part of the problem with science literacy both inside and outside the classroom is that many of us have the wrong idea about what science is to start with. That is, I hope, what the takeaway message of my post was.

  8. What every College student need to take is is a course in the scientific method and process. This is a good start on that course.

  9. I agree with the article, but I have found the principal issue to be misinformation dissemination. Most often, the author is “preaching to the choir,” no matter what each of us reads, because we search out articles on issues we wish to know more about or that interest us. So, for my parents, FOX news will always be the authority and it won’t matter what any professional tells them otherwise. I have learned, sadly, that some people are unreachable.

    • Hi Gregory — agreed: misinformation dissemination is certainly a big problem, and we all naturally gravitate towards what we want to hear. I still think that part of my job as a scientist, in what capacity I can, is to show people both the scope and boundaries of science as a discipline. Not everyone will listen, but my hope (perhaps naive) is that I might reach some people on the fence, or put out some more information on how science as a process works. I think we are just so polarized right now politically, that all of us (me included) have this knee-jerk reaction to see things through that prism. One of my goals in the public sphere is to show that science is a tool, not political or faith-based propaganda. I wish more of us could see that data don’t care about your political leanings, philosophy, or values — but I also believe that we cannot divorce the implementation of science from being human. I am no philosopher, but my non-scientifc, non-Ph.D. hunch is that we will have more success tackling issues such as climate change if can meld data with emotion and action.

  10. Pingback: Forum Friday « paleoaerie

  11. We as a race are programmed to not believe things are true, or likely to happen, until they actually do happen. It’s human nature.

    • Hi Jerry — whereas I agree that we often wait until the last minute to do something about our issues, I am hopeful that there are solutions to this problem. Something as simple as conserving our oil and gas is a good first step, and something that has immediate environmental and monetary impacts.

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