In (Consensus) Denial
The clear scientific consensus about human-caused climate change (certainly between 90-100% of experts, and most likely somewhere around 97%) presents a big problem for the contrarians. Namely, most people have neither the time nor the inclination to sift through the evidence for themselves, so they tend to defer to the majority of experts. Therefore, if the contrarians want to keep the masses from demanding action to reduce human-caused climate change, they need to cloud the public’s perception of the scientific consensus. That’s exactly what retired atmospheric physicist Dick Lindzen does in a new video called “Climate Change: What Do Scientists Say?” produced by “Prager University”. In this post, I will point out some clear instances where Lindzen obfuscates the issue. He’s so good at the Art of Lying Well (TM) that he can do it without making any factual claims that aren’t technically true (in a sense that almost none of his viewers would understand). But first, here’s the video.
“Prager University” (hereafter PU) is not a real university, per se. Instead, it is a website created by well known conservative talk radio host, Dennis Prager, where 5 minute videos about various topics are posted. The purpose of PU, according to Prager, is to counteract the “unhealthy” intellectual and moral climate of the American system of higher education. I’ve watched a few PU videos, mainly because they show up on my Facebook feed, and have had mixed reactions. Some of the videos I’ve seen bring up important philosophical points, such as this one about abortion, although they definitely come from a politically and socially conservative point of view. I have no problem with the videos when they argue for a particular point of view (especially since I am politically and socially fairly conservative), but some of them have seemed astonishingly naive, ignoring easily anticipated counterarguments. (E.g., see this one about progressive income taxes.) Suffice it to say that PU videos sometimes make interesting arguments, but I wouldn’t trust them to provide a fair discussion of alternative (i.e., more liberal) points of view.
Given that human-caused climate change is practically a taboo subject in conservative American politics, it’s no surprise that PU would produce a video attempting to downplay the scientific consensus. But to their credit, PU chose perhaps the most well credentialed climate change contrarian they could find, Richard Lindzen, as the star of the show. Dick Lindzen is a retired Professor of Atmospheric Sciences at MIT, and is universally acknowledged to have made several valuable contributions to the field of atmospheric physics. He is one of the few climate change contrarians who have really solid credentials in the field, and even scientists who have pointed out flaws in Lindzen’s reasoning have acknowledged that even when he’s wrong, he at least raises interesting questions.
Smoke and Mirrors
In the PU video, however, Prof. Lindzen leaves out quite a lot of pertinent information to make himself seem more mainstream than he actually is among climate scientists, and uses easily misinterpreted language to brazenly mislead his viewers. Here are several examples.
1. Lindzen divides the scientists involved into two groups: 1) those associated with the IPCC, who “mostly believe that recent climate change is primarily due to man’s burning of fossil fuels… [which] might eventually dangerously heat the planet,” and 2) “scientists who don’t see this as an especially serious problem.”
All of that is true, but Lindzen neglects to inform us about the relative size of the two camps. Some might object that “science isn’t about consensus” (which is misleading, at best), but it seems pretty obvious that your average Joe watching a five-minute video on “Climate Change: What Do Scientists Say” isn’t looking to carefully weigh all the arguments that any scientist anywhere might happen to put forward. He just wants a quick, representative summary of what scientists are saying, and a ballpark estimate of the level of agreement.
Take, for example, Lindzen’s statement that scientists associated with the IPCC “mostly” believe human-caused climate change is a serious issue. Does “mostly” mean 51%? 75%? 90%? 99.99999999%? I can’t give a definitive answer, either, but I can take a crack at it. Marc Morano (a former staffer for Senator James Inhofe) issued a report which “features the skeptical voices of over 1,000 international scientists, including many current and former UN IPCC scientists, who have now turned against the UN IPCC.” I once combed through this report to find out which IPCC scientists had “turned against” the IPCC, and found that Morano produced quotations from less than 1% of the authors and less than 1% of the reviewers of the IPCC report. Let’s just say that describing >99% agreement as “mostly” seems a bit coy. Could there have been more dissenters who weren’t as forthcoming about their views? Sure, but even if we assume that there were ten times as many as Morano found, that still leaves us with >90% agreement.
Even worse than his obvious attempt to downplay the level of agreement within the IPCC camp, Lindzen makes absolutely no attempt to give his viewers an idea of how big the group of contrarian climate scientists is, relative to the entire community of climate scientists. When the opinions of two groups of experts are reported without any indication of their relative sizes, people tend to assume the sizes are at least roughly comparable. This is clearly not the case, according to several studies.
2. When Lindzen describes the opinions of the contrarian scientists, he says “We note that there are many reasons why the climate changes…. None of these is fully understood, and there is no evidence that CO2 emissions are the dominant factor.”
Look at how Lindzen begins his description–“We note….” This language seems to indicate that the ideas about to be mentioned are simply facts to be pointed out, rather than opinions. And in fact, the idea that there are a number of factors that influence the Earth’s climate, none of which are fully understood, seems completely uncontroversial to me. Physicists don’t fully understand things like “light” and “matter,” either, but that doesn’t mean that they don’t have perfectly serviceable theories about these subjects that fairly accurately predict the behavior of light and matter. So what?
However, Lindzen also “notes” that “there is no evidence that CO2 emissions are the dominant factor.” What? NO evidence? If, by “evidence,” he means “absolute proof,” then sure, science never produces “absolute proof” of anything. That’s Philosophy of Science 101. But if, by “no evidence,” Lindzen means there are no facts that can be legitimately used to argue for the belief that CO2 emissions are (at least lately) the dominant factor driving global warming, then his statement is an astonishingly brazen falsehood. See this article in Science magazine and this talk by Professor Richard Alley (Penn State), for example.
3. Lindzen also lists several points of agreement between mainstream climate scientists and the contrarians, and while these points are largely accurate in a technical sense, he crafts his language to make it sound like these points of agreement support the view that we shouldn’t be worried about human-caused climate change, or that we can’t possibly know enough to evaluate the risk.
Lindzen describes one of these points of agreement like this. “Over this period, [the] past two centuries, the global mean temperature has increased slightly and erratically, by about… 1 °C. But only since the 1960’s have man’s greenhouse emissions been sufficient to play a role.” There are a number of problems with this phrasing, but the most egregious is Lindzen’s use of the word “slightly”. Certainly a 1 °C change in temperature isn’t much compared to how much temperature swings in a given locality between day and night, or between Summer and Winter at high latitudes, but a 1 °C change in global mean temperature turns out to be quite a bit more significant. Consider, for instance, that the difference in global mean temperature between now and 20,000 years ago is only about 4-7 °C, but back then there were miles-thick ice sheets covering much of North America and Eurasia. It is similarly uncontroversial to say that human greenhouse gas emissions weren’t really large enough to play a big role in global warming until the 1960’s, but once again Lindzen leaves out plenty of pertinent information. For instance, there has been about a 0.8 °C rise in the global mean temperature since the 1960’s, during which time natural climate drivers, like changes in the incoming solar radiation, have been pushing toward a cooler climate.
In other words, the bit about the temperature changing “slightly and erratically” by about 1 °C over 200 years is a red herring. In fact, the global mean temperature meandered up and down a little over this period, right up until human greenhouse gas emissions became the dominant factor. Since then, the planet has been heating up relatively rapidly and consistently.
And that’s the point. Lindzen’s claim that climate scientists generally agree “the climate is always changing” is true, but the fact is that none of them are worried about climate change unless it happens faster than ecosystems human civilizations can successfully adapt to avoid major upheaval. Remember how, during the last ice age, the global mean temperature was something like 4-7 °C colder than now? Well, it took about 10,000 years for most of that change to happen. Humans appear capable of raising the global mean temperature by several degrees in one or two hundred years, by contrast.
Lindzen’s last point of “agreement” among climate scientists is also technically correct, but so deceptively phrased it almost beggars belief. He claims, “Given the complexity of climate, no confident prediction about future global mean temperature or its impact can be made.” He backs up this assertion by quoting the 2007 IPCC report, which says that “long-term prediction of future climate states is not possible.” Hearing this, our average Joe watching the five-minute video to find out “What Scientists Say” would undoubtedly come away with the idea that even the IPCC admits the models IPCC scientists use to make projections about future climate states are worthless. This is clearly not the case, however, and to understand what is going on, we need quite a bit more context.
Let’s start with a more complete quotation of the IPCC report.
Further work is needed [to]… [i]mprove methods to quantify uncertainties of climate projections and scenarios, including development and exploration of long-term ensemble simulations using complex models. The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible. Rather the focus must be upon the prediction of the probability distribution of the system’s future possible states by the generation of ensembles of model solutions. Addressing adequately the statistical nature of climate is computationally intensive and requires the application of new methods of model diagnosis, but such statistical information is essential.
Ask yourself this. If climate models aren’t good for anything, why is the IPCC recommending further work to quantify uncertainties in model “projections and simulations”? The key to understanding this is the way in which scientists use the terms “prediction” and “projection”.
When we say “prediction,” we mean a statement about what will happen at some specified future time. Climate models don’t do “predictions” for multiple reasons, only one of which is the complex, chaotic nature of the climate system. This simply ensures that no prediction can be overly precise, whereas a bigger problem is that we have no way of knowing how several important model inputs will change over time. For example, how will volcanic activity change over the next century? We don’t know. How will solar radiation change? We don’t know. And most importantly, how much greenhouse gas will humans pump into the atmosphere? Well, that’s exactly what people are trying to decide, isn’t it? We could drastically cut emissions, or we could keep ramping them up as the Earth’s population grows and becomes more industrialized. This is by far the biggest uncertainty for climate “prediction”.
When we say “projection,” however, we mean an estimate of what might happen IF a certain scenario plays out. A model “projection” of future climate states must be based on a number of assumptions about what humans will do, and what natural climate drivers will do. How well the actual climate follows such projections depends, in large part, on how well future reality conforms to the assumptions made.
In the paragraph quoted above, the IPCC report was simply saying that since it’s impossible to precisely “predict” future climate states, climate scientists should put some more work into quantifying exactly how uncertain various aspects of the climate model “projections” are, so that when they run “projections” for different possible scenarios, they can do a better job of quantifying the probability of different possible outcomes. That’s why, instead of using a single climate model to make projections, the IPCC uses an “ensemble” of models that cover the spread of uncertainties in various aspects of the climate system. And if we can quantify the probability of different outcomes, given certain courses of action, we can go on to estimate how risky those courses of action might be.
4. Lindzen wraps up his presentation by implying that climate scientists aren’t worried about climate change, and the only reason anyone is worried is that politicians, environmentalists, and media-types are pushing their agendas. Oh, and other scientists (which happen to include a whole lot of climate scientists) are jumping on the bandwagon.
The concept of “risk” is central to the message the IPCC is trying to get across, and essential for understanding how Dick Lindzen obfuscates the scientific consensus. When he wraps up his presentation of supposed points of agreement between the IPCC and “skeptic” camps of climate scientists, he says,
The scenario that the burning of fossil fuels leads to catastrophe isn’t part of what either group asserts.
But if the viewer understands that climate scientists try to estimate the probability of different outcomes, and the risks involved, it is clear why Lindzen’s language is once again misleading. Of course climate scientists don’t “assert” that “burning fossil fuels leads to catastrophe.” That would be idiotic. Rather, almost all of them claim that there is a strong probability of outcomes many people would call “catastrophic” (like millions of people being displaced from their homes in low-lying areas due to sea level rise) if people don’t fairly rapidly curtail their use of fossil fuels.
He goes on:
So why are so many people worried, indeed panic-stricken, about this issue? Here’s where Group 3 comes in: politicians, environmentalists, and media. Global warming alarmism provides them, more than any other issue, with the things they most want. For politicians, it’s money and power. For environmentalists, it’s money for their organizations, and confirmation of their near-religious devotion to the idea that man is a destructive force acting on nature. For the media, it’s ideology, money, and headlines. Doomsday scenarios sell.
See how he does that? Lindzen first makes a statement that sounds striking, but in retrospect is revealed to be a pedantic statement of the obvious. He then implies (without actually stating) that if actual climate scientists don’t “assert” that “burning… fossil fuels leads to catastrophe,” then they must not even be “worried” about it, and then blames the “worry” on several groups of non-scientists.
Don’t get me wrong–some members of the groups Lindzen blames sometimes do exaggerate climate change risks. It’s a complicated subject, and people are people, after all. But the implication that climate scientists aren’t even “worried” about the risks posed by uninhibited burning fossil of fuels is patently absurd, and Prof. Lindzen certainly knows better.
What he says next provides some insight into how he probably justifies this chicanery.
Meanwhile, over the last decade, scientists outside of climate physics have jumped on the bandwagon, publishing papers blaming global warming for everything from acne to the Syrian civil war.
Wait! Up until this point, Lindzen never specified that the scientists he was talking about were “climate physicists.” Certainly climate physicists like himself are important players, but many others, including ecologists, biologists, chemical oceanographers, agricultural scientists, doctors, economists, geographers, and so on, are clearly needed to assess how the projected climate changes would affect anything people care about. But Prof. Lindzen wants to exclude all these others, and only allow climate physicists, who can say something about the probability of different changes in temperature and precipitation patterns under different scenarios, in the discussion. In other words, we can argue about how much the temperature will rise if we burn so many billion tons of coal, but we aren’t allowed to discuss how such changes would affect people and ecosystems.
The sheer battiness of this line of argument would become even more evident if we were to poll just the climate physicists about whether they are worried about the risks posed by unabated fossil fuel burning. In fact, I know a number of bona fide climate physicists (including some of Lindzen’s former students,) and I can assure you that they are worried about it. Consider, for instance, this essay by Ray Pierrehumbert, Professor of Physics at Oxford University (formerly the U. of Chicago), and author of Principles of Planetary Climate, a graduate textbook on climate physics. (In case you don’t click the link above, I should point out that the title of Prof. Pierrehumbert’s article is, “Climate Change: A Catastrophe in Slow Motion”. Did you catch the word “catastrophe”?)
[NOTE: So what if someone, somewhere published an article about how hotter temperatures promote acne, or that enhanced heat and drought in a desert can lead to civil unrest. I have no idea how much evidence there is for either of these propositions, but they don’t sound particularly stupid to me.]
If the purpose of this Prager University video is to inform viewers about “What Scientists Think” about climate change, it’s an utter failure. Viewers without much prior knowledge of the subject would certainly come away with several false ideas about the opinions of the vast majority of climate experts.
If the purpose of the video is to be misleading propaganda, however, it’s at least mediocre. Consider this description of the Art of Lying Well (TM) by science fiction Grand Master, Robert A. Heinlein.
It’s not enough to be able to lie with a straight face; anybody with enough gall to raise on a busted flush can do that. The first way to lie artistically is to tell the truth — but not all of it. The second way involves telling the truth, too, but is harder: Tell the exact truth and maybe all of it…but tell it so unconvincingly that your listener is sure you are lying. (Robert A. Heinlein, Time Enough for Love)
Almost everything Lindzen says in the video could be interpreted as technically true, but he leaves out so much pertinent information that his statements are almost guaranteed to be misinterpreted. In fact, the clear direction of his arguments makes absolutely no sense, unless his factual claims are misinterpreted.
Lindzen needs to work on his game, however, if he wants to get away with this kind of propaganda. His presentation is so far from telling “the exact truth and maybe all of it” that anyone even slightly familiar with the subject would be aghast at Lindzen’s shameless manipulation of his audience.