[bobthepanda]

We don’t need to do much of anything, but tall buildings are fine, given that they minimize the land impact of a given amount of square footage, and denser communities have lower land footprint and lower per capita carbon emissions.

(European cities are plenty dense at moderate heights, but they also offer much smaller living quarters than American ones; a Parisian studio is in the range of 9-35 m^2 whereas an average Manhattan studio is 51 m^2, and most Americans would consider it small.)

[ericmay]

Skyscrapers specifically (tall buildings depends on definition of height), but they’re very energy intensive. You can only operate, construct, and maintain them with cheap oil.

The problem isn’t density (most European towns are perfect here actually) but too much density. Manhattan is the opposite spectrum of suburbia, and neither are very desirable. France actually does this well in Paris, as you mentioned. The American thing to do would be tear down every arrondissement and replace with skyscrapers. Paris sort of made that mistake with part of the city before they stopped.

I have to imagine that it's not that skyscrapers are great for emissions, but that the suburbs are just abysmal and so everything looks good in comparison.

Walkable neighborhoods and bike-friendly development in mixed-use medium density areas is probably the best. The main issue with suburbs is that you have to drive everywhere, not necessarily the density.

[bobthepanda]

Operating them is not that expensive. A building's heating and cooling needs are proportional to surface area, not volume, and in a given apartment building the vast majority of walls are shared with other units instead of outside. So a taller building is more and more efficient with regards to climate control, unless it doesn't contain a whole lot of volume. The Burj Khalifa is obviously not ideal but at least judging by, say, Hong Kong the optimal sweet spot for a building is 30-40 stories, where you're not running into massive extremes of either cost or carbon emission.

The reason the suburbs perform so poorly is, among other things, transport very quickly becomes the largest contributor to emissions. Hong Kong is so dense that not only is the "fifteen minute city" more than a reality for non-work trips, but most people are within a 15 minute walk or bus ride of massive shopping malls with department stores.

That being said, the end picture looks fuzzy after some more searching, mostly because it's hard to isolate variables about cities (their wealth, their climate, etc.) and also because the definition of what a "city" is varies globally. Other than "very car oriented suburbs with large lots and home sizes are big carbon emitters per capita."

[dzhiurgis]

Ask people where would they rather live Hong Kong or Auckland (being second worst sprawl after LA)...

[bobthepanda]

Ask people if they would prefer to work or win the lotto.

It's impractical for everyone to win the lotto.