[rayiner]

Manufactured goods, food, and clothing. Note that we tend to think of these things as not being a big deal, but that’s colored by the fact they’re so cheap. In 1970, a wall mount AC was about $400, when the median family income was under $10,000. Lots of people simply could not afford one. Today, a wall mount AC is still $400, while the median family income is over $80,000. People dismiss the fact that an AC unit has gotten 90% cheaper in real terms. But you wouldn’t do that if everyone in your family was huddled around a single AC unit in one room during a southern summer, as was very common in the 1970s.

[inigyou]

Average temperatures were also lower in 1970 and we didn't put as many of the jobs in places where you absolutely needed an AC.

What's average income less average house price? Has that gone up or down?

[rayiner]

> Average temperatures were also lower in 1970

Yes, but not enough to change whether you want AC or not: https://www.extremeweatherwatch.com/cities/washington-dc/yea.... In DC in 1970 you had 98 days above 85 degrees. The year before was 80 and the year after was 71. Last year was 72 and the year before was 93. There are more warm days, but you wanted an AC in the DC area back in the 1970s too.

> and we didn't put as many of the jobs in places where you absolutely needed an AC

I don’t think that’s true. The south and mid atlantic was always a huge share of the population. And the midwest was a bigger share than today, while the temperate west coast was a smaller share. You need AC in Chicago too: https://www.extremeweatherwatch.com/cities/chicago/yearly-da.... Even in the 1970s in Chicago you had 30-60 days over 85 every year.

[vel0city]

> The south and mid atlantic was always a huge share of the population.

The population share of the South and West regions of the US have grown while the population share of the Northeast and Midwest have shrunk.

https://www.census.gov/popclock/data_tables.php?component=gr...

What are the fastest growing metro areas in the US these days? DFW, Austin, Houston, Phoenix, Orlando, Atlanta, Raleigh, Tampa, Nashville. Which ones are in the cooler parts of the country?

I agree overall its not like half the population moved to the Sun Belt, but a pretty large amount of the population growth in the US has been focused on the hotter parts of the country.

You're pointing to days over 85 as days you need AC. To me that's pretty warm, but not unbearable. Days where it never goes below 80F for a week or more at a time, or places with extreme humidity mixed with such high temperatures, now that's a place where you need AC.

[rayiner]

> Which ones are in the cooler parts of the country

There are very few “cooler parts of the country.” Europe’s “no AC” culture was because, until the 2000s, almost everywhere had less than 15 days a year over 30C (85F). There’s only a handful of cities like that in the U.S., such as San Francisco and Seattle. Even in the northern latitudes the U.S. gets really hot. Cedar Rapids, Iowa, averaged about 50 85F+ days a year in the 1970s. Boston and Minneapolis were in the 30-60 range during that decade.

To put that into context, Germany over the last decade is seeing 15-20 30C+ days a year. It hit 30-31 only in two years recently, 2018 and 2019. Those years had 7,000-8,000 deaths each year. Germany’s epic heatwaves killing thousands of people was a mild summer in Cedar Rapids or Boston or Minneapolis even in 1970.

The U.S. is just a very hot country, even in the northeast and upper midwest. AC is a huge, lifesaving standard of living improvement almost everywhere in the country. And we shouldn’t take for granted the developments that enabled 88% of the country to have access to that technology.

[TimorousBestie]

To your point about high humidity exacerbating heat, I think it’s relevant to consider wet bulb globe temperatures (WBGT) instead of air temperature. It’s more objective than heat index or the ad hoc “feels like” metrics. Above 30-35C WBGT, humans start dying without intervention.

In the United States at least, days with high WBGT have increased and more places experience them. I hear the same is true also in Europe.

[swiftcoder]

They are increasing in Europe, yes, and unlike the American southwest, any sort of artificial cooling is pretty uncommon in most of Europe.

On the flip side, the cost of cooling is steadily falling due to government incentives to replace oil-fired boilers with heat pumps, and the rapid growth of solar driving down daytime market prices for electricity.