The climate aspect is most definitely covered in the article.

As for the bus issue, most sources I found (eg, https://www.theguardian.com/us-news/ng-interactive/2017/dec/...) show that the flow is _out_ of the big coastal cities when it occurs.

I'm sure there is more nuance, but zoning and the lack of true market forces to build more and denser housing seems to be a very large piece of the puzzle.