Much of the US already had warmer summers than Europe when the impact of climate change was smaller, so AC is far more common.
But I'm very sceptical of those numbers. They are apparently even worse for cold, and you can't attribute that to lack of airconditioning. I still think the huge difference can only be attributed to a difference in reporting.
Cuts both ways.
Extraordinary claims require extraordinary evidence doesn't cut both ways.
For example: https://www.nber.org/digest/aug19/official-statistics-overst...
> In September 2022, a vicious heat wave enveloped much of the western U.S., placing tens of millions of people under heat advisories. Temperatures across California soared into the triple digits. Sacramento broke its heat record by more than 6 degrees Fahrenheit when the temperature hit 116 degrees.
> California death certificates showed that 20 people died as a result of heat-related illness from Aug. 31, 2022 to Sept. 9, 2022.
> But a study last year by California’s Department of Public Health found that death rates increased by about 5 percent statewide during the heat wave, causing 395 additional deaths.
https://www.scientificamerican.com/article/u-s-deaths-from-h...
Excess mortality studies seem to show about 24 per 100,000 excess deaths from heat in Europe vs 6 in US/Canada.
I'd love to see an age adjusted figure as well as it's likely Europe has likely more very old people and my guess is that heat/cold mortality is concentrated in the very old people.
Much of the US is extremely unpleasant without air-conditioning for a substantial portion of the year so of course everyone living in those parts installs it.
Could this be made the basis of an efficient cooling system?
You are starting to see a lot more external AC (heat pump?) units jerry-rigged into the sides of multi-unit dwellings, though.