Bette Midler recently blamed “ignorant selfish climate deniers” for the uncommonly warm winter weather:

Dec. 22, 2015, 63 degrees in NYC. I would like to thank the ignorant selfish climate deniers for all their goodwill toward the planet.

Midler is just another in a long line of climate change activists who can’t seem to get the hang of this whole critical thinking thing. Midler’s tweet is all the more puzzling when you consider that just last year she blamed cold weather on climate change:

If you live in The South and still believe Climate Change doesn’t exist, wake up. And buy a snow shovel

Hmmm. So, the data doesn’t really matter at all, does it. Any data, no matter how disparate, just confirms your view? Here’s a question: What would it take to disprove anthropogenic climate change theory? It’s a question I wish were asked with greater frequency. For the time being, let’s just look at the informal fallacies involved in Midler’s tweets:

1. Ad hominem. She calls climate change deniers “ignorant” and “selfish.” That’s not an argument. It reminds me of the Monty Python “Argument Clinic” sketch where a guy pays for an argument and gets abuse instead:

A: SHUT YOUR FESTERING GOB, YOU TIT! YOUR TYPE MAKES ME PUKE! YOU VACUOUS TOFFEE-NOSED MALODOROUS PERVERT!!!

M: Yes, but I came here for an argument!!

A: OH! Oh! I’m sorry! This is abuse!

M: Oh! Oh I see!

A: Aha! No, you want room 12A, next door.

I wish I could say that to the climate change faithful: “Please show me to room 12A because I came here for an argument.” They’d probably call me a vacuous toffee-nosed malodorous pervert and tell me to shut my festering gob.

2. Confirmation bias. If it’s cold, it’s climate change. If it’s warm, it’s climate change. If there are big hurricanes, it’s climate change. If there are no hurricanes, it’s climate change. If Antarctic ice is receding, it’s climate change. If Antarctic ice is growing, it’s climate change. Everything and anything confirms climate change, apparently. If that’s not confirmation bias, I don’t know what is. Under the umbrella of confirmation bias is cherry-picking (where only favorable data is emphasized), special pleading (where unfavorable data is suppressed), and the anecdotal fallacy (where someone’s personal experience—like, “Hey, it’s warmer than usual today. Global warming”—is used as evidence for a conclusion).

One of the most important things to remember about confirmation bias is that you don’t have to be an idiot to fall prey to it. Leo Tolstoy seemed to think that smart people were more susceptible to it, actually, because they had usually done more work to arrive at their wrong conclusions and therefore had more to lose if they changed their minds:

I know that most men—not only those considered clever, but even those who are very clever, and capable of understanding most difficult scientific, mathematical, or philosophic problems—can very seldom discern even the simplest and most obvious truth if it be such as to oblige them to admit the falsity of conclusions they have formed, perhaps with much difficulty—conclusions of which they are proud, which they have taught to others, and on which they have built their lives.

Thanks, Leo. That about sums up the situation with climate change activists. And speaking of “very clever” people who won’t let go of “conclusions of which they are proud, which they have taught to others, and on which they have built their lives,” perhaps now is a good time to bring up the sacred cow of climate change—scientific consensus. Which leads me to my third major fallacy cluster:

3. Appeal to authority. Apparently, “scientists” agree that climate change is true. And most politicians too. The only people who won’t accept it are the ignorant selfish anti-science backwater gun-cradling yahoos from the sticks. I get it. A lot of smart people have bought into anthropogenic climate change theory. I won’t call them stupid for doing it. It’s often the smart thing to do. If you’re a Democrat or a climate scientist, you would be an idiot to publicly deny climate change. Because you’d lose your job.

The fact is that most people on both sides of the climate change debate have picked a side for political, not scientific, reasons. Maybe you’re a Republican, and you want to appeal to your voter base and your friends in Big Oil. Well, you need to deny climate change. If you’re a Democrat and you want to appeal to the Prius drivers and stick it to the greedy capitalists, you need to confirm climate change. The difference is that climate change deniers generally can’t appeal to authority. So they’re safe from at least that informal fallacy. It’s the climate change activists who are constantly talking about the scientific and scholarly consensus when, at least logically speaking, it doesn’t matter.

All in all, climate change activism has become a clinic in informal fallacies. Actually, you can pretty much close your eyes, open a book on informal fallacies, and put your finger down at random to find another problem with climate change logic. I’ve merely scratched the surface here, but feel free to fill in the gaps. It’s easy, and it would almost be fun if it weren’t so depressing.