My ongoing annoyance with the on-a-mission climate change deniers in this country (they are less common elsewhere for various reasons, but especially because it has become a partisan issue and one of our political parties speaks in an increasingly singular voice of insanity) has just been matched by Meg McArdle. She’s not a denier, she points out, rather she’s a moderate, an independent voice. This is the same territory she stakes out in her political opinions. She’s splitting the difference between whatever positions can be found on any given issue. If you don’t know, this is called the Middle Ground Fallacy.
This fallacy is committed when it is assumed that the middle position between two extremes must be correct simply because it is the middle position. this sort of “reasoning” has the following form:
- Position A and B are two extreme positions.
- C is a position that rests in the middle between A and B.
- Therefore C is the correct position.
This line of “reasoning” is fallacious because it does not follow that a position is correct just because it lies in the middle of two extremes. This is shown by the following example. Suppose that a person is selling his computer. He wants to sell it for the current market value, which is $800 and someone offers him $1 for it. It would hardly follow that $400.50 is the proper price.
What is the middle position between those who believe we are being visited by UFOs and those that don’t? That we are sometimes visited by UFOs but not as often as some claim? And yes, I do think climate change denial (aka climate change skepticism) is of a kind with those that believe in conspiracies of other sorts, like UFO visitation. That’s not ad hominem, I really do think it’s coming from a common instinct. It’s not that some of the the science supporting climate change could be wrong – some of it almost certainly is and we’ll discover what holds up and what doesn’t as evidence accrues.
But, here’s McArdle pontificating from, as far as I can tell, no evidence whatsoever other than her gut instinct:
What’s at stake is the degree of warming associated with our carbon dioxide emissions. In particular, to what extent the earth’s many complex and not necessarily well understood feedback systems may mitigate (or exacerbate) temperature increases. I’ve long been skeptical of the more catastrophic scenarios, because all this carbon used to be in the atmosphere, which probably defines a ceiling on how bad it will get–a ceiling well below “WE’RE ALL GOING TO DIEEEEEEEE!!!” That said, I wouldn’t really want to live in the Jurassic, and not just because I’m afraid of hundred-foot lizards. (for example, I am also afraid of the huge flying roaches Palmetto bugs that live in our nation’s more southern climes). So that doesn’t mean I don’t worry quite a lot.
I have no idea where she gets the idea that “all this carbon used to be in the atmosphere”. I can’t even imagine what she even means by this. Is “all this” shorthand for “a lot“? Pretty sloppy writing if that’s the case. Or does she believe that fossil fuels is carbon that settled into the earth from the atmosphere? Egads. The best evidence (note the citations are from the journals Science and Nature and not simply yanked from the author’s behind) suggests that the levels of carbon in the atmosphere are higher than at any time in the past 15 to 20 million years!
“We then applied this technique to study the history of carbon dioxide from 800,000 years ago to 20 million years ago,” she said. “We report evidence for a very close coupling between carbon dioxide levels and climate. When there is evidence for the growth of a large ice sheet on Antarctica or on Greenland or the growth of sea ice in the Arctic Ocean, we see evidence for a dramatic change in carbon dioxide levels over the last 20 million years.“A slightly shocking finding,” Tripati said, “is that the only time in the last 20 million years that we find evidence for carbon dioxide levels similar to the modern level of 387 parts per million was 15 to 20 million years ago, when the planet was dramatically different.”
My opinion matters just as much as Meg McArdle’s. Which is to say, not at all. Don’t listen to individuals. Argument from authority is just another fallacy (and George Will is not an authority in any case). If evidence arises that things aren’t as dire as current predictions, take it in. You’ll also want to discount much of what you find on Google. There is a fancy graph out there showing no correlation between CO2 and temperature but if you look at the home page of the sites publishing this stuff you’ll invariably find organizations or individuals who are dedicated to the denialists’ claims, and not to discovering truth.
I think it’s important to remember than scientists are contrarians. It’s a large part of my attraction to science – it debunks commonly held beliefs again and again. The scientific method is based on falsification of data, not on confirming what you already believe to be true. I’d like to say that there’s hope that the evidence for human-caused climate change will be overturned but that’s unlikely given the fact that the evidence is from many different lines of inquiry. If the worst that happens is a proliferation of Palmetto bugs as McArdle fears we’ll all be very, very lucky.
This fallacy is committed when it is assumed that the middle position between two extremes must be correct simply because it is the middle position. this sort of “reasoning” has the following form:
1.
2. Position A and B are two extreme positions.
3. C is a position that rests in the middle between A and B.
4. Therefore C is the correct position.
This line of “reasoning” is fallacious because it does not follow that a position is correct just because it lies in the middle of two extremes. This is shown by the following example. Suppose that a person is selling his computer. He wants to sell it for the current market value, which is $800 and someone offers him $1 for it. It would hardly follow that $400.50 is the proper price.
