Yesterday I started a response to this article, which seems to me fits cleanly into a science-denial format. The author is making a lawyers case against the notion of climate change, using classic denialist strategies. Yesterday I focused on his denial that scientists can ever form a meaningful consensus about the evidence, conflating it with the straw man that a consensus somehow is mere opinion, rather than being based on the totality of the evidence. Today I am going to focus on the notion of “post-normal” science. Macrae gives this summary of what post-normal science is:

“The conclusions of post-normal science aren’t ultimately based, then, on empirical data, with theories that can be rigorously tested and falsified, but on “quality as assessed by internal and extended peer communities,” i.e., “consensus,” i.e., informed guesses.”

This is another straw man. He is creating a false dichotomy here, based on his misunderstanding of science (he is a journalist, not a scientist). Yesterday I gave this summary of how science works:

“Science is not a simple matter of proof. There are many different kinds of evidence – observational, experimental, theoretical, and modeling (computer modeling, animal models, etc.). Scientific evidence can use deduction, induction, can start with observation or start with a hypothesis, can use theoretical constructs, can make observations about the past and make predictions about the future. All of these various activities are part of the regular operation of science. No one type of evidence is supreme or perfect – they all represent different tradeoffs. Scientific conclusions are always a matter of inference – scientists make the best inference they can to the most probable explanation given all of the available evidence. This always involves judgement, and some opinion. How are different kinds of evidence weighted when they appear to conflict?”

He seems to believe that the only “real” science is one based on pure evidence, requiring no opinion or judgement – but this does not exist. There is no proof in science, only inference based on the evidence, which is always partial and imperfect. But this is the strategy of science denial – create an artificially narrow definition of science (which may sound reasonable to a non-scientist) then try to exclude the science you want to deny from “real” science. So, evolution deniers claim that no exploration of the past can be “real” science because you cannot do repeated experiments on the past. No one was there to observe it. Now Macrae is saying we cannot do science about the future, because you can’t experiment on the future, only make “guesses”.

Macrae is also repeating another common evolution-denial tactic of saying that climate change cannot be falsified. He has to go there because his notion that you cannot do science about the future is obviously false when you consider that science often functions by predicting what will happen in the future, and that such prediction can potentially be falsified. He claims climate models are not real science (they are one piece of doing climate science) because even if they are wrong, climate scientists don’t change them. But in order to make this point, he has to misrepresent how well the climate models over the past 50 years have matched actual warming.

To do this he again employs a common denial tactic – reference outliers that agree with your position. There are three prominent climate change denying scientists that always seem to be quoted – Lindzen, Spencer, and Christy. A thorough exploration of their claims is beyond this post, but suffice to say, they are a minority opinion, far from the  mainstream of their field. Every field has such outliers. Again – this is why we look to see if there is a consensus in a discipline, to see where the weight of opinion is. Otherwise you can play – choose your own expert – to find whatever opinion suits you. In this case, Macrae cites Christy to claim that climate models have over-called warming. He states this as a fact, without disclosing that Christy’s analyses are controversial at best, and clearly in the minority.

Here is a good review of climate models by an academic source. They conclude:

“Climate models published since 1973 have generally been quite skillful in projecting future warming. While some were too low and some too high, they all show outcomes reasonably close to what has actually occurred, especially when discrepancies between predicted and actual CO2 concentrations and other climate forcings are taken into account.”

You have likely seen these projections, with a line surrounding by a zone of uncertainty, projecting temperature into the future. Actual warming has been within this zone (within 2 standard deviations from the average predicted warming). What they mean by taking discrepancies into account – if you ran a model in 1980 and plugged in a predicted amount of CO2 release, but the actual CO2 releases was more or less, the model will be off not because it doesn’t work, but because the wrong amount of CO2 was entered. We can then run the model again with the correct CO2 and see how its predicts warming. But even without this, the models have done generally very well. They are not perfect, but accurate, and are being tweaked all the time to get more sophisticated and more accurate.

Much of what Macrae says after this is based on the false premise that climate models don’t work but scientists ignored this – hence climate science is not falsifiable. But this is nonsense – most analyses find that the climate models work just fine.

Macrae also, even within his false premise, is committing another denialist trope – saying that because the models were allegedly off (they weren’t) they are therefore wrong. Evolution deniers do this a lot as well – because scientists were wrong about the branching pattern of evolutionary relationship among certain species, perhaps evolution did not happen at all. Even though the cherry-picked outlier he chose shows the models were off, they still predicted warming and the globe is warming. They were correct about the direction and persistence of warming, just off in terms of magnitude (again, according to Christy, but not the majority of climate scientists).

Taken together these strategies that Macrae is using are common among many campaigns to deny accepted science (accepted because the totality of evidence favors those conclusions). But of course, he denies the denial, even while blatantly engaging in it.