Atmospherically speaking

Was chatting to a warmist chum the other day in the coffee shop who thinks I'm a very ignorant person for not believing in the 'CO2 drives the climate' meme. He treats me with the same attentive fanaticism an ardent missionary gives a pagan native. I for my part, treat him with an amused tolerance like that reserved for next doors precocious children.

He's always trying to 'convince' me (the poor fool) about Carbon Dioxides deleterious effects on the atmosphere and temperature. Take for example yesterday when he trotted out the old 'but look at Venus' argument with me.
"You know Bill, all this Carbon Dioxide we're putting out. Some day soon we're gonna end up like Venus. I mean, really."
"Really?" Quoth I.
"Yeah, it's a classic demonstration of the runaway greenhouse effect."
"Is it? I thought it was because Venus is much closer to the sun and has a thick atmosphere that boils landing craft." I replied.
"No, hey. Look at how much CO2 there is in Venus atmosphere, yeah?" Here he paused for dramatic effect. "Ninety five point six percent! No wonder it's so hot."
"And..." I said, with a rising inflection.
"Jeez Bill! You been taking the stupid pills, or what?"
"No."
"All that Carbon Dioxide has doomed Venus to be a hell planet!" He declaimed.
"What about Mars?" I cocked an eyebrow.
"What about it?"
"Ninety five point three two percent Carbon Dioxide." I countered with an amused smile.
"Yeah but the atmospheric pressure is way lower!" He protested.
"Why do you think that is?" I asked carefully. I like the guy, but he's not that savvy when it comes to the solar system.
"Well it's further away from the sun!"
"Yes. And your point is?" I said, pausing to take a sip of coffee and wait for his latest declaration of faith. I was greeted with silence. "Look." I said, trying not to sound unkind. "Venus, Mars and Earth are three totally different planets in different orbits. You can't expect to compare one with the other."
"Yeah, but Earth could end up like Venus!" He persisted.
"Only if you shifted Earth forty odd million kilometres towards the sun. Besides, Venus is a younger planet, at least as far as the surface is concerned."
"Hey, what happened to its oceans then?" He rejoindered, still determined to defend the Carbon meme by all means possible.
"What oceans?"
"The ones it used to have."
"Says who?"
"Scientists. You know."
"Really? Which ones?"
"You're asking for evidence again, aren't you?" He said a little sheepishly. "I don't know which ones."
"I think the study you were referring to was published in the late eighties." I remarked, trying not to sound unkind. "To the best of my recollection it only said there might have been oceans on Venus, not that there ever really were. Although if water formed that close to the sun, well, wouldn't it have been too hot to form oceans of liquid water?"
"Well, Bill. How come Earth's oceans haven't done the same?" He challenged with that slightly smug air of one about to strike a winning blow.
"Let me see now; where do you want me to start?" I was desperately trying not to yawn. Why are so many otherwise intelligent people convinced of this dumb idea? "Earth is over forty million kilometres further out from the sun than Venus."
"So what?" He challenged.
"Ever hear of the inverse square law applied to solar radiation?"
"What's that?"
"Simply put, the closer you are, the hotter it gets, and it isn't a straight line relationship, it's a curve." I saw the bemused look on his face. "Say the sun is here." I put my empty coffee cup on the table. "Venus is here, and Earth is here." I shoved a couple of cookie crumbs roughly into position. "How much more energy does Venus get from the sun than Earth?"
"About half as much again?" He hazarded.
"Wrong. Around one hundred and ninety percent more. Add to that Venus has no real magnetosphere to deflect the solar wind. Therefore it cops the lot. Solar flares, everything. The only shield it has against solar radiation are high level cloud layers."
"Huh?"
"All the clouds of Sulphuric acid etcetera, etcetera." I did the Yul Brynner wave from the King and I. It was wasted. Heavy sigh. "In addition, Venus has no solid nickel iron core like Earth and no plate tectonics. No nickel iron core means no protective magnetic field. No plate tectonics mean no effective heat circulation within the core. This means all the energy from the core goes into keeping the crust red hot. Venus' hot crust superheats its lower atmosphere, and the thick upper clouds prevent a heat loss rapid enough for Venus to cool. It's catching it from both directions. That's why Venus is so hot."
"Say again?"
"Venus has no real magnetic field, yes?" I ticked it off on my finger.
"If you say so."
"Check it out for yourself. Google Venus magnetic field."
"Okay."
"Earth has a magnetic field." I ticked off another point.
"For sure, everyone knows that."
"Right. Earth's magnetic field acts as a partial shield against the worst of solar radiation. Got that?" And another.
"I'm good with that."
"Venus is almost a third closer to the sun than Earth without Earth's magnetic shielding." This is getting hard work, I can see his eyes glazing over, and I can feel mine glazing over as well.
"Hey, how come if Venus has no magnetic field that it has a thicker atmosphere?" He smirks, thinking he's caught me out. "Wouldn't a thicker atmosphere be to do with the Carbon Dioxide? Hey, and if there's no magnetic field, what keeps the atmosphere in place?" He concludes with an air of triumph.
"Magnetism and gravity aren't the same thing. Look it up." Was that a sigh creeping into my voice? I knew I was fighting a losing battle with his attention span, but I ploughed on regardless. I was also straining my memory to come up with this stuff. What I really needed at this point was a decent text book. "It's not so much the Carbon Dioxide it's more the clouds keeping the heat from the crust in."
"So, nothing to do with Carbon Dioxide then?"
"Not so much." I conceded.
"Not so much? Are we backtracking a little here, Bill?"
"The point I'm trying to make is that CO2 is a very small part of the picture." I said (Slightly heavily at this point). "All the scare stories you read in the media about Earth turning into Venus are just that; scary stories to frighten the kiddies."
"Oh." His eyes went blank for a moment.
"I don't believe them any more."
"So you're still a denier then?" He teased.
"There's nothing to deny." I chuckled. He's a trier. Sometimes very trying.
"So all these people saying CO2 causes global warming don't know anything about it?"
"They're mainly media types and politicians. What do you think?" I said.
"How come they say so?"
"Because they probably don't know any better."
"How come you know?"
"Because I actually do research for my Science Fiction writing." I said with lead in my speech. This was getting really hard work. No one pays me for this, so why do I bother?
"And they don't?"
"Doesn't look like it. They just don't have the time for proper research I guess." I shrugged. "It's kind of like the Piltdown Man hoax. Someone plants fake fossils to prove a fake theory of racial superiority. All the vested interests agree because it suits their agenda, a lot of ordinary people get taken in because they want to believe, the news media don't care so long as they sell copies, and by the time the truth leaks out forty years later, everyone is too damn embarrassed to acknowledge they were wrong. Fancy another coffee?"
"No; gotta go. See ya Bill." And he left, leaving me feeling oddly tired. Not that he'll believe a word I say. Hell, if I pointed out a nice sunset he'd check the TV news to see if it was really happening.

And people ask me why I'm so cynical sometimes.