Earlier quoted context omitted.
No offense, but your thinking here is actually a bigger part of the problem. There is nothing fundamentally unsustainable about suburbs, single family homes, low density, or cars. 50% of the USA is totally uninhabited, and it is possible today to build a totally off-grid and sustainable single family home / suburb in the majority of it. You can even capture carbon in concrete. Don't prescribe solutions just because y…
The incentive is already set, city limits are already set, eventually they will fill up and then people will be motivated to build up a bit. Sure, fundamentally nothing is sustainable because eventually the useful energy gradients where life can thrive will run out as the universe expands into a cold dark empty vacuum. But before that let's try to spend the already fixed tax income a bit more efficiently. Compact cit…
Citation needed on cities being fundamentally more efficient. A suburban home can be powered by pure solar, rainwater/groundwater can be captured and recycled locally, an electric car can carpool, and mass transit (sure, let's build more of that too) can easily reach out to the suburbs. You can even telecommute, and that sipping straw of electrons makes the public transit users look like energy-guzzling planet-killers in comparison (Ooh! We all love some tasty moral superiority!)
Even if that weren't the case, there is such a concept as efficient enough. At some level, sanity factors in, and trying to raise a family while dodging needles and poop in San Francisco is enough to make some people say "enough is enough."
I'm all for spending smarter and more compassionately. San Francisco spends $240 million per year on homeless programs, or $30k/yr per individual. And it doesn't even make a dent; the local living costs are so high that $30k evaporates in the blink of an eye.
We need policies/infrastructure that encourage building up AND out to relieve this pressure and better care for the less fortunate people ... while still allowing for sustainable urban and suburban lifestyles.