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.
