Reality Check

Postcards from the Edge

In my previous column, I wrote about letters I receive from non-scientists questioning global warming. This month, I dig deeper into the mailbag to write about two types of correspondence I receive from scientists and engineers.

The first type comes from scientists and engineers who have decided that climate science is “weak.” They find flaws in the way climate scientists understand the scientific method and apply it. The second type of mail comes from climate scientists who question, perhaps, the consensus conclusions on climate change.

Logical flaws

As with the earlier correspondence I described, many of these letters share a common feature: the presence of logical flaws. The writer will focus on a particular aspect of climate science and selectively exclude evidence that does not support their thesis. This is a form of cherry picking. It leads to an interesting conundrum of a credentialed scientist who maintains a fundamentally flawed argument — often supported by special interests or paid consultants.

Those who maintain that climate science is “weak” science often express discipline superiority or arrogance. Several of these writers are physicists. They tend to feel their training imbues them with fundamental insights that climate scientists have missed. I, like many of my colleagues, started as a physics major. When I told my undergraduate advisor I was considering meteorology or oceanography, he made it clear that all of those problems had been “solved” in the mid-19th century.

Culture wars

This raises an interesting aspect about the culture of science — basic versus applied research. I prefer the term “use-driven research” to applied research. Our culture loves basic research, the exploratory kind in which the goal is to produce knowledge, not solve a specific problem. Basic research often leads to conclusions that eventually find a revolutionary application. Hence, we never know when the research might pay off. This is a valid argument, but not the only reason to pursue scientific investigation.

Use-driven research, on the other hand, has more direct consequences. What happens if we learn something that people do not what to know? For example, burning fossil fuels, which brings us wealth, might make the planet unbearably hot in a few centuries.

When I worked at NASA, I wrote tedious memos regarding the public and legislative support of space science versus Earth science. It is extremely cool to see those amazing pictures of Pluto, but it is quite disturbing to see rapidly rising sea levels. There is something fundamentally human in this point. (It’s like the difference between people who want to know if they have a genetic marker to get a rare disease 30 years from now, and those who prefer to wait and see.)

Cause and effect

Earth Day Founders

Six members of the original 1970 Teach-in for the Environment reconvened in March 2020. (Image: Michigan Photography.)

Discipline arrogance creates a more complex scenario than the standoff between basic versus use-driven research. The complexity of mathematics often is used to evaluate the sophistication and virtue of scientific research. It’s as though mathematical prowess equates to rigor. This assertion is both flawed and, at times, discriminatory. (Some might like this short story.)

Those who consider climate science “weak” also tend to believe science is achieved solely by the design of controlled experiments that prove cause and effect, i.e., that water boils at 100 degrees C (212 degrees F). They disregard the reality that when studying complex natural systems, such as our climate, it is not so easy to establish cause and effect beyond a shadow of a doubt. And there are countless examples of natural science (biology, chemistry, and physics) in which we establish knowledge, including cause and effect, without the benefit of controlled experimentation.

The challenge of consensus

As I dig a little deeper in the mailbag, I am sure to find additional correspondence that labels me a liar. Sometimes a writer suggests a hellacious end for me.

These writers tend to have a problem with the “consensus approach” to establishing the credibility of a body of knowledge. Some of this is psychological: Is the herd always right? The short answer is no. One might look back on the motivated reasoning of investigations of human race and intelligence. This line of herd thinking perpetuated itself well into the 20th century.

However, there is tremendous value in the development of consensus that emerges from competing explanations of a phenomenon.  A classic example of this is the ozone hole. In the beginning, some scientists maintained atmospheric motions (dynamics) caused the ozone hole; others cited chemical destruction as the cause. In this case, chemistry played a dominant role. It should be noted the motions of the atmosphere not only set up the conditions for the chemistry to occur, but also caused transient low values of ozone. Consensus emerged on the chemical causes; now we regulate ozone-destroying chemicals and can observe the recovery of ozone.

The case of the ozone hole is common; namely, most phenomena are not “caused” by a single factor. This fact challenges those whose philosophy of science is anchored in singular cause-and-effect experimentation.

Consensus, like many other concepts, can be powerful or weak. So how do we manage the power of organizing within a community’s body of knowledge (consensus) while also choosing intelligent ways to challenge the consensus because it might be wrong? This is the actual work of science.

Uncertainty abounds

Beyond concerns about consensus, climate science is characterized by uncertainty, and some of those uncertainties are monstrous. Scientists even choose to make that uncertainty their area of study. Some focus solely on the uncertainties associated with global climate models and conclude that those uncertainties are so significant they are unusable.

In a similar vein, some maintain that since weather, two weeks from now, cannot be predicted by what we know today (deterministically), that climate cannot be predicted.

These sources of uncertainty and the question of “how predictable is our climate” challenge both scientists and non-scientists. How do we quantify and describe uncertainty? How do we place it into context? How do we keep it from paralyzing us? These are sticky questions, especially if one’s philosophy requires uncertainty to be quantified and minimized for the knowledge to be “right.” In this case, the future climate is unknowable.

From my perspective, information about uncertainty is like information about observations. Different knowledge arises from different sources. The scientist has the job of considering the information as a whole.

Using knowledge for good

Scientists are human, and humans interpret the world as individuals. Humans have complex beliefs, not all of which derive from scientific evidence. Religion is a powerful belief system, often used to reach contradictory conclusions on whether humans should address climate change. For some, these beliefs trump science and absolve humans from any responsibility.

All of the scenarios I’ve described here are based on individuals’ beliefs and philosophies. Beliefs about climate change can be deeply held. And sometimes they are the result of superficial self-interest.

I conclude that, yes, global climate models bring large uncertainties. However, when used as guidance in concert with observations, fundamental physical laws, and complementary models developed to understand uncertainty, we can be unequivocally certain of one thing: In the coming decades, the planet will warm, sea level will rise, and the impacts on humans and ecosystems will be far-reaching.

A well-challenged consensus aligns behind this, and I believe it is our responsibility to use this knowledge to advance the common social good.



  1. Adam Bosch - 1996

    Good Morning Richard,

    I appreciated your article. Thanks for leading from the front regarding climate change.

    Kind Regards,



  2. Roger Harris - 1981

    While I can agree that there has been some warming of the climate in the recent decades it is not apparent to me that the cause has been clearly defined and that the effect will be totally detrimental. The draconian “fixes” that are being proposed are to me far worse than the evident impact of the warming that we can observe. The “crisis” declarations that the world will change dramatically for the worse seem to be little more than scare tactics to achieve compliance with certain groups’ objectives rather than rational predictions based upon reality.


    • Richard Rood

      Hi, thanks for writing.

      I am interested in what would “clearly define” the cause for you. There is a science of attribution, which uses multiple techniques to determine the relationship of our warming to the various waste products of fossil fuels and food production. One technique, based on signal to noise analysis, finds that we are far more than 99.5% certain that carbon dioxide is responsible for the warming. You might find it interesting to poke around with the search terms “attribution climate change” and “Ben Santer” to see if you find something that is convincing.

      As for “totally detrimental,” one of the challenges of climate change communication is that we are early on the warming curve. It is like COVID when there were 10, 20, 40, 80, 160 cases. Did not seem like a lot, but that was consistent with a growth curve.

      There is another challenge, because, to some, now and the next couple of decades there will be a climate “optimal.” That will be transient. In a 100 years, those who find climate change beneficial will be smaller and smaller percentages. But the more important point will be societal disruption, displacement from coasts, drying up of some agricultural areas (California will be an interesting case study this year.). Those climate winners will, of course, find it difficult to exist next to the climate losers.


      • Paul Gross - 1983

        I want to add one thing to Ricky’s reply. There are three main things that control a planet’s average temperature: proximity to its star (in our case, the sun), it’s surface albedo (color), and the composition of the planet’s atmosphere. There are some who say that the Earth has been very warm in the past, and the current warming is just a part of that. Wrong. All of those previous warmings have been attributed to astronomical changes involving the earth’s rotation, orbit, etc. Over the past 150 years, neither those astronomical changes nor any changes in Earth’s surface albedo have occurred. However, it is documented scientific fact that humans have changed the composition of our planet’s atmosphere. That is the only thing that has changed enough to cause the rapid, unnatural current warming. The basic physics are actually simple: heat equals energy in minus energy out. Adding more heat trapping gases to the atmosphere, thus, raises the planet’s average temperature. Is the warming linear? Of course not. Is it even across the planet? Of course not. Does a particularly harsh winter mean that the warming isn’t happening? Of course not. The overwhelming balance of scientific evidence shows that our planet is warming, and that the proximate cause of that warming is human activity.


  3. Larry Junck - 1976

    My thanks to Professor Rood for this excellent article that informs us how consensus contributes to scientific knowledge. Consensus is at its strongest, in my opinion, when it considers a wide range of evidence and a large number of scientists, conditions that apply to our knowledge of climate change.

    The idea that, who knows, maybe something good will come out of climate change, seems like a dangerous idea. Do we really want to choose to accept loss of biodiversity, threats to our agriculture, rising oceans, extreme weather events, and increasing health problems, all long-term consequences of climate change, in the vague hope that something good might come out of it?


  4. Bill Myers - 1973

    With thousands of variables affecting a scientific conclusion, singling out one factor is a thankless task.

    Global warming/climate change (use of one term or the other often charaterizes one’s belief in it or not) will not likely yield one factor, but a multiplicity of human-induced behaviors that can be remedied by human action. The “costs” of reducing greenhouse gases (say capturing leaking methane at the wellhead) are often offset by the potential economic recovery of that released gas. Similarly, reducing combustion products usually lead to lower levels of atmospheric pollution, and lower death and morbidity rates among affected populations. So, there is a worldwide societal benefit being achieved by these policies.

    In terms of “proof,” everyone will adopt her/his own standard concerning whether the planet is warming as well as its causes. My profession — the law — uses three standards to assess whether “facts” have been proven. First, “preponderance of the evidence (the lowest standard)” which essentially makes it a “more likely than not”. This standard is usually looked at similarly to a 51-49 standard.

    Second, “clear and convincing” evidence is one that convinces the fact-finder that the evidence is so relatively strong that one can make predictions as to future conduct and thereby affect substantive rights (the standard used to evaluate whether a parent should have her/his parental rights terminated).

    The third, and final standard is the “beyond reasonable doubt.” This is the standard by which society deprives individuals of her/his right to freedom within society. It is not a standard of ‘beyond all doubt,” but one in which reasonable people are convinced, taking all factors into consideration, that certain facts have been established.

    The evidence supporting global warming, in my view, meet the two stronger standards. As such, it is foolhardy to give the atmosphere more ammunition to create more environmental refugees in the coming decades. (The sad fact that a homeowner less than one half mile and 10’ above sea level from the Atlantic Ocean would waste the US’s time assisting climate deniers for 4+ years should cause us to redouble our efforts to address this serious issue).


  5. Jennifer Buckingham - 1999

    Thank you for this article! It was very interesting and seriously could be applied to the pro/anti vaccine arguments currently going on….or Covid origins, masks, etc. etc. People claiming “science” behind this or that. Arm-chair quarterbacks of sorts, making decisions based on snippets of this type of information. It’s a frustrating thing! I really appreciate your perspective in this article. I’m going to share it with my Geologist husband as well! 🙂


  6. Sushil Birla - 1997

    Prof. Rood, this is a thought-provoking article, touching upon topics which are broader than climate and space sciences, e.g.: Reasoning/argumentation (ref. Toulmin); fallacies of logic; modeling; analysis and treatment of uncertainties. It reminded me of the saying, “All models are wrong; some are useful”. For example, even if meteorological models might have relatively greater uncertainty in predicting the weather at a certain time two seeks from now, the models are able to predict seasons well, and could show long-term trends with much lesser uncertainty than the weather two weeks from now. Many differences across scientists can be traced to differences in the underlying assumptions or the validity of these assumptions..


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