It's widely understood that urban sprawl has the highest environmental impact in addition to the highest traffic death risk and many other social problems.

https://www.nature.com/scitable/knowledge/library/the-charac...

https://www.oecd.org/env/rethinking-urban-sprawl-97892641898...

https://www.mdpi.com/2071-1050/12/11/4445/pdf

In financial terms:

- https://www.strongtowns.org/journal/2021/8/4/the-question-ev...

- https://www.strongtowns.org/journal/2020/11/11/poor-neighbor...

This series goes into more detail about the unsustainable aspect specifically: https://www.strongtowns.org/the-growth-ponzi-scheme