>I think it's possible if we start building new cities designed for walking, instead of just expanding our current cities, with all the problems that presents. I think the trick would be to strictly limit their footprint to something that would allow anyone to walk from one end to another in ~30 minutes. You can still have a big city, you just have to rely on the world's greatest form of public transportation (the elevator) and build up.
We can build new cities, or expand current ones, with concepts in place that eliminate the need for travel, but a more pressing problem that requires immediate attention is the population currently in cities.
In the given circumstances, mass public transport systems (like the one envisaged by Musk) are the best way forward, IMO.
Electric cars are the next best option, considering the overall eco-friendly nature of coal to miles drive efficiency of electrical systems, plus their suitability to go off grid.
To me one major focus point seems to be investment in technologies, concepts and constructs of nano-grids, at the level of individual communities and homes, drastically reducing fossil fuel usage. This could be a major push point for governments, and yes, problems of this scale require massive push from governments, to pull people kicking and screaming into a greener future, before it's too late. For that the world need strong leaders and forward thinkers.
To quote an example, in India, where I am from, the govt. is pushing very hard for solar power generation, to the detriment of existing thermal power plant manufacturing infrastructure. There is a lot of resentment in affected companies, vendors, operators, etc, for this move. But what has to be done has to be done. Left to their own, or to market forces, we will boil ourselves dead.
Remember, climate change has a lot of lag. It's effects are not immediate, nor apparent until it is too late. We are already seeing that now.
> Aside from the serenity of not having cars wiz around, dividing up the city and running people over, there are a bunch of other benefits. Not having to provide services to every residence makes the government's job much easier (so less government); the city would become more of a community if everyone is always walking everywhere and running into each other; you'd have more public green space since the city would be surrounded by a large green loop; and it could fit into some really amazing locations, like a lush valley, or between a lake and a mountain. You can connect a bunch of them with a hyperloop (or something as simple as a bus service).
This seems too fantastical to be made true in reality. Maybe I'm wrong, but IMO it's better we plan and do things keeping in mind the nature of the average human. After all, we still have huge swaths of population still thinking climate change is not caused or accelerated by human activities.