Denial of anthropogenic global warming (AGW) comes in a variety of flavors. While i’ve come across several taxonomies, the most elegant (and, so far as i know, the only one necessary) classifies AGW denialists into three camps:
- Global temperatures are not rising.
- Global temperatures are rising, but not because of human activity.
- Human activity is causing global temperatures to rise, but this is not a big problem / we can’t do anything about it.
Two clarifications are in order: First, i use the term “denialist” to refer to people who specialize in rhetorical and pseudoscientific tactics to obscure some reality, usually in defense of some ideological agenda that reality threatens. I think of people who buy into their propaganda as “deniers”, but seeing as they’re victims, too, i don’t like using the term. Second, and in keeping with this choice, those who believe that AGW is reality, but who downplay its implications or our power to mitigate them, clearly don’t deny AGW but are AGW denialists. This is because their advocacy for inaction feeds (typically by intent) into the broader AGW denialism campaign (which wouldn’t exist in anywhere near the numbers it does in the absence of powerful interests who feel threatened by the implications of AGW for policy, business, or even worldview).
The stage set, enter Roanoker Wallace Mayo, who had an opinion piece published in the RT Tuesday. Mayo is “sure that we have experienced global warming for some time now” but “equally convinced that the man-made portion is negligible”, which situates them in the second camp above, and devotes most of their piece to providing an alternative explanation for various phenomena—the shrinking ice shelf, rising sea levels, more frequent and severe extreme weather events—he seems to view as the key evidence for AGW.
It’s a good exercise in science literacy to pick a claim from Mayo’s piece and carefully investigate it. (I think he’s actually right about one or two things.) So as not to spoil the opportunity, i’ll just pluck one needle from the porcupine:
I find it interesting that there have been significant snows reported in many unusual places in the Northern Hemisphere last winter.
Now, my first thought was that Mayo was simply committing the base rate fallacy. Given that snowfall is variable, and that there are a lot of places that snow does fall, by chance alone we should expect quite a few places to receive inordinate snowfall in any given year. (This might be tempered somewhat by broad trends in weather that produce similar effects over whole continents in a given year, but i suspect that it’s still true.) Logical fallacy! Nothing more to see here.
It turns, out that my skepticism was misdirected. My go-to source for climate change controversy contextualization, John Cook’s amazing Skeptical Science website, has the following to say (with sources) about what have actually been recent record snowfalls:
To claim that record snowfall is inconsistent with a warming world betrays a lack of understanding of the link between global warming and extreme precipitation. Warming causes more moisture in the air which leads to more extreme precipitation events. This includes more heavy snowstorms in regions where snowfall conditions are favourable.
Perhaps i don’t pay enough attention to the weather. Chalk up one point for consulting the experts, and one caution against knee-jerk skepticism.
Finally, it’s illustrative that Mayo is able to say the following without irony:
I am bothered when some commentaries and letters to this paper have touted the line: 97 percent of climate scientists agree that global warming is running out-of-control and is man-caused. Yet, more than 1,000 international scientists, including many current and former United Nations IPCC scientists, strongly dispute the claim of man-caused change. Even if “climate changers” are a small majority, perhaps you’ve heard the maxim: Majority may rule, but majority is not always right.
Scientists are human, scientific conclusions are provisional, and even scientific consensus is fallible. Still, it takes an incredibly potent cultural potion to overcome the almost reflexive acceptance with which we welcome the vast majority of scientific findings. (When was the last time someone denied that exoplanets are being discovered, or that bees communicate by dancing, or that blood is mostly water?) Mayo makes the very good point that harping on the vast consensus of expert opinion is not a winning strategy, or at least not enough of one. What could be?