People should really stop growing megapolises and start developing smaller cities, interconnection infrastructure and regional decentralization (decentralization is already fine in the US with its states system but near-zero in e.g. Russia (Moscow everything) and I dunno about Indonesia).
Basically all of Java is as dense as a mid-sized American city. Java (2903 / mi^2), Atlanta (3547 / mi^2). Here, Java's population density includes its 12000-foot peaks. Or, to give an alternate picture, it's a third of the size of California, with four times as many people.
