Critical Thinking Note 3: Earth Week Edition

Why Climate Skeptics are in Denial

The fossil fuel constituency has long exploited popular misunderstanding of the logic behind the science of climatology and I think this calls for a re-appraisal of how we teach the so called “scientific method.” As long as there is money in coal and oil, we should expect to hear from its constituency. But we needn’t fall for their obfuscations.

In high school science classes, students are typically taught that science discovers things about the world through inductive generalization. We find patterns in the evidence we observe and base our expectations of the future on those observed patterns. Certainly science does often employ this pattern of reasoning. But as an account of the methods of science, simple inductive generalization is a sadly impoverished model. And sadder yet, it is a model that leaves people very vulnerable to being easily mislead about the nature of the science at issue. For we all know that trends don’t always continue. Housing prices went up and up and then they went down. It is currently spring and we are experiencing a warming trend that we know full well will end in a few months. When people, in line with what they were taught as “the scientific method,” are reminded that trends don’t always continue and that induction only gives us reason to think that observed patterns are, to some degree or another, likely to continue, they are ready and primed to hear the climate denier as the voice of reason when he says “who’s to say current warming isn’t just a natural cycle?” or “why think changes in climate are caused by human activity?”

But alas, this is not the structure of the reasoning at the core of climate science.  In fact, scientists employ rich and subtle combinations of induction, deduction and inference to the best explanation in puzzling out how nature works. In the case of climate science, our original grounds for concern that humans may be changing the climate in dangerous ways do not appeal to observed warming trends at all. The warming we have observed only further confirms what we already had reason to worry about based on what we can deduce from what we know full well about the causal powers of various gases and our practices of freely releasing these into the atmosphere.

We know full well that CO2 traps heat. This is easy to demonstrate in the laboratory. Simply place a person on one side of a glass chamber and an infrared camera on the other. The infra-red camera will pick up the heat image of the person when the chamber is full of air. Increase the concentration of CO2 in the chamber and you can observe the heat image of the person on the other side steadily fade away. CO2 is transparent to visible light, but opaque, like a cloud of smoke, to infra-red light, the wavelength of electromagnetic radiation that disperses heat from the planet back into space. We have known this about CO2 for well over a century and our understanding of the green-house effect that keeps the biosphere of our planet temperate as based on the heat trapping properties of CO2 and other gases dates back about a century as well. Now we reason deductively. Given its heat trapping causal power, if we increase the concentration of CO2 in the atmosphere by releasing lots of it through fossil fuel combustion, then extra heat energy will get trapped in biosphere. Of course we know something about how much carbon we release burning fossil fuels. Next, the fundamental laws of physics tell us that matter/energy is never created or destroyed. It follows deductively from this that extra heat energy trapped in the biosphere must go somewhere and do some work. Now notice that our way of life, our economy, where we live, our water supply and our agriculture are all finely tuned to the relatively stable climate humans have enjoyed over our brief history on the planet. Given this, it should be clear that throwing lots of extra energy into our climate system is highly likely to make trouble for us. The conclusion is pretty clear before we’ve looked at a single thermometer. Be concerned about human induced climate change.

Call this the core argument for concern about anthropogenic climate change. Now go listen to the many climate deniers and let me know if you catch any of them addressing the core argument in any way. I’ve been listening for 25 years or so and I have yet to hear any climate denier offer any plausible objection the core argument. The logic of the argument is clear enough. So which premise of the argument would the climate denier have us reject? Would he deny that CO2 traps heat? That we release very large quantities of it? That the consequences are likely to be bad for us? In the absence of any plausible reply to the core argument, I’d suggest you doubt the climate denier’s intellectual integrity.

Critical thinking is not like basketball. It’s simply not a matter of who can score the most points. If your opponent has a good argument and you have no good objection to it, you lose. It doesn’t really matter what climate deniers find in stolen e-mails or how easy they find it to make fun of Al Gore. If they have no plausible reply to the core argument for concern about climate change, then they just aren’t taking the science seriously. And if skeptics aren’t taking the science seriously, then they don’t deserve to be taken seriously.

Russ Payne

April 25, 2013


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