1/4 This is not exactly my field and the answer will depend on how you define "sustainability". That said, here's a brief thread discussing two decent studies that consider the effects of urban form on some specific aspects of "sustainability" ... https://twitter.com/DrCameronMurray/status/1355422137683599361

2/4 First, Bento et al. (2005) find "moving sample households from ... Atlanta to ... Boston reduces annual VMTs by 25%." In other words, changing urban form while holding demographics constant leads to 25% less driving, which can be expected to have some environmental benefits.

3a/4 Second, Ahlfeldt and Pietrostefani (2019) review and analyse the effects of density on various socioeconomic and environmental outcomes, including car travel, energy consumption, and air quality. P.s. And some other interesting outcomes, like subjective wellbeing.

3b/4 Ultimately, A&P find higher density leads to:
- less vehicle travel (elasticity -0.06)
- energy consumption (elasticity -0.07)
- worse air quality (elasticity 0.13)

That is, it depends!

4/4 So, if we want to increase density *and* be more "sustainable" in a broad sense, then we probably want to think about policies to mitigate the negative effects of density on local air quality. Like pricing parking and roads.