Well, that was interesting.

Some quick thoughts below the cut.
So I’ve recently become much more aware of the Discourse about air conditioning that is common to much of northern Europe. There’s a lot of weirdness generally, but there are certain strains that pop up regularly.
One is Left / green concern about emissions. Unlike a lot of Left / green concerns, this one doesn’t stop at hand-wringing. It tends to go straight to moral condemnation and direct action. A surprising lot of northern European greens view aircon as somewhere between “acceptable only in the direst of needs” and “just inherently very wicked”.
Another is a strain of what I can only call machismo. Find an online discussion about aircon, and within a few comments you’ll find the guy — it’s always a guy — who wants you to know that he was with British Forces Arabian Penninsula at Aden back in the day, and nobody had ever heard of this aircon nonsense, and they were just fine, damn your eyes. Or the guy — it’s always a guy — who is living in a house his great-grandfather built with his own two hands, insulated proper-like and with real brass fittings, warm in winter and cool in summer, add a ceiling fan and that’s all a man should ever need.
Related to that last one is Anything But Aircon. You see, if you just install a geothermal heat pump, and get better insulation, and plant trees around the house and ivy on outer walls, and add awnings and external shading, and paint your roof white, and get double- glazed windows with louvers, and a ceiling fan in every room, and fill your living spaces with large house plants, and also sleep with a mattress topper and 100% breathable linen or high-thread-count Egyptian cotton sheets, then you should be completely fine.
Yet another is, not exactly anti-Americanism, but defining-us-against-Americanism. Those huge malls — icy cold, I needed a sweater! Have you heard they have stadiums that are air-conditioned? And ice in their beer!
Apropos of that last point. Here’s a temporal heat map of London:

and one for New York City:
— But NYC has a relatively mild climate by North American standards. Here’s Kansas City:
In Kansas City, nature is actively trying to kill you quite a lot of the time. There’s literally no place in Europe, from Cornwall to the Urals, that has a climate as extreme as Kansas City.
And these are the temperate parts of the USA — the bits where average temperatures are comparable to much of Europe. I’m not even going to bother with maps from Houston or New Orleans or Los Angeles.
Do Americans overuse aircon? Oh yes, we absolutely do. But do we need aircon? Also yes. Most of us do, at least some of the time. There are a couple of corners of the country where it rarely gets that warm — upper New England, a strip along the Pacific coast, the airier bits of the mountain West. But around 80 percent of the US population lives in places where summers without aircon are not just unpleasant, but actively bad for mental and physical health. 99% of homes in Houston have aircon. And if you’ve ever spent a summer in Houston, that statistic will leave you wondering how there can possibly be 1% that don’t.
On the positive side, the US has built about all the aircon it’s going to.
This is very much not the case around the world! Here’s a projection of the growth of aircon worldwide.
And, you know, aircon saves hundreds of thousands of lives worldwide every year. Heat stress and dehydration are killers, especially for small children and the elderly. Workers are more efficient with aircon, and children learn better, and hospitals with aircon have better outcomes for the sick and injured. And do you really want to tell the gasping family in Uttar Pradesh, hey, sorry folks but no aircon for you — we have to pull that ladder up behind us, for the good of the planet?
Air conditioning currently causes around 3.6% of greenhouse gas warming. In terms of CO2, it’s a bit less — around 2.7%. But a lot of aircons use refrigerants that are greenhouse gases in their own right, so that bumps the total up.
Looked at one way, aircon produces more emissions than the entire aviation industry. That’s a lot! Looked at another way, we could turn off every air conditioner on the planet tomorrow, and a couple of billion people would be miserable, and hundreds of thousands would die, and there’d be massive economic and social disruption and… we’d reduce emissions by a barely noticeable 3.6%.
That said, more aircon is going to mean more emissions and more warming. So, by selfishly trying to cool ourselves, are we going to cook the planet?
Well… like everything related to climate change, it’s a bit more complicated. For one thing, aircon designs have become dramatically more efficient in recent years. And we’re not even close to the thermodynamic limits, so there’s every reason to think further advances are coming. Current thinking is that increases in efficiency will claw back between a third and half of the increase in electricity demand. So, still not great, but less bad.
Also, electricity in 2050 is going to be, worldwide, a lot less carbonized than it is right now. If you’re running your aircon off solar, wind, hydro, or nuclear, you’re not generating any emissions. And by 2050, hundreds of millions of people will be powering their aircons with low- or no-carbon electricity. Again, still not great, but much less bad than if we added all those aircons today.
And, you know, the folks in Uttar Pradesh and Nanjing and Kinshasa are going to get their aircon. That is, as it were, baked in.
I’ll end with one other fact. I mentioned that aircon produces more emissions than the entire aviation industry. But aircon produces only about a quarter as much emissions as heating. For some reason a lot of people code heating as a necessity of life and aircon as a luxury. Is that objectively correct? I’m not sure.
Anyway. Aircon: it’s complicated.



