One of the discussions going on now in New Zealand is what a future city should look like. One of the major reasons for this is that planners have decided that they should restrict urban sprawl, and to do this they have withheld planning permission to open up new land. That is all very well, but they have not facilitated any alternative, and hence all that has happened is that house prices have actually soared, especially in Auckland where, for some reason, immigrants come and do not proceed further. The problem with the compact city is that even if you decide you need it, you need land to build whatever the extra people are going to live in. The inner city tends to be already built on.
Why does it matter what our cities evolve into? While it is possible, and necessary, to have biofuels, it is most likely that they cannot produce enough to replace oil. I have sent quite a lot of my professional working time involved with this issue, and with one possible exception, it is physically impossible to find enough biomass to power future usage assuming we continue with present trends. People talk about hydrogen to replace oil. In my opinion, that would be a mistake. Hydrogen is one of the hardest gases to store, since it leaks given the slightest plausible excuse. Once it has leaked, it has a very large range of mixtures with air that are explosive. It is reasonably easy to ignite, and as was part of my ebook Puppeteer, a terrorist could do serious damage. The gas is just too dangerous. There have been proposals to store the hydrogen chemically and slowly release it. An example would be compounds based on ammonia/borane, but the problem then is, where to find the energy to make the compounds, and how to teach the general public how to handle the chemicals safely.
The other alternative is to cut down drastically the amount of fuel consumed. In my most recent futuristic novel Dreams Defiled, one of the major protagonists must deal with this problem and comes up with the scheme: arrange it so that wherever possible, everyone walks or cycles to work. How can that be arranged? Simply by dispersing work into small island communities, and have everyone who works at a site live nearby. The argument to sell this scheme was, why spend two hours going each way to and fro work? If everyone lived close to work and had the ability to purchase groceries close by, fuel consumption would drop dramatically, and now I think biofuels could make up the rest. The problem then is, how to persuade people to move, and how to provide something suitably attractive for them so they are happy to move. One of my thoughts is that when planners set out to redesign a city and ask people to live in a different type of house/apartment, the planners should be the first to move. That way, at least the housing is far more likely to be livable.