Then I traveled to Spain in August and was hosted at someones house for a week. They had no AC. And their method is simple: split the day in two resulting in the siesta. During the day in the intense heat you're tired by 3 PM and nearly dead by 5. The Spaniards? They go home and go to sleep for an hour or two then wake up when the sun has gone down and it cools down. Most things close at 5PM and reopen around 8PM. People stay out late too - I saw parents chatting on benches at a playground after midnight while their children played.

We have ways around this heat problem. Though I know people so spoiled that they INSIST their home and workspace must be at 60F even in 100F heat. They'll burn forests just so they wont be inconvenienced by a bead of sweat.

(Of course, the ideal scenario is not that rising carbon emissions from increased cooling get offset by lower emissions from decreased heating, but rather that we transition to abundant carbon-free energy from solar, wind, nuclear, etc. and are able to keep our houses as cool as we want in the summer and as warm as we want in the winter without any environmental consequences.)

[0] https://ourworldindata.org/grapher/co2-heating-cooling

I made a slightly-snarky comment along these lines once, and a fellow commenter on HN pointed out how efficient air conditioning is. For one, it's always accomplished via heat pump; eg, moving heat, so the only byproducts are electricity consumption and waste heat. We know how to produce clean electricity. On the flip side, heating indoor spaces also produces waste heat, but a lot more of it. Much worse, the vast majority of home heating (at least in the US) is done by burning fossil fuels. If you compare the heating demands of the northeast to the cooling demands of the south, in terms of BTUs, the heat demands are way more intensive.

The most important factor in this equation is the temperature change required. The temperature differential between a winter temp of 20 or 30F to an indoor temp of 70F requires SO much more energy than cooling from a summer temp of 90F to indoor temp of 70F.

So I can remain smug about living in a mild climate in the Bay Area; my total energy consumption is much lower than the average home. But I probably shouldn't feel smug about not needing A/C when the real problem is the gas furnace I run every morning and part of the day, for months on end, from November to March.

(My house is actually currently missing several walls; the gas furnace has been thrown in the trash and it's being replaced with 3 heat pumps, which will give me both A/C _and_ more efficient heat. No thanks to PG&E, which will reward my GHG reductions by charging me out the ass for the electricity required to heat my home).