Climate change is another wild card that could have a significant impact on how both developed and developing urban centres play out in the future. Around 60% of all cities that currently have a million residents or more are at risk of at least one type of major natural disaster, many of them climate-related, and even the most well-organised, highly developed cities have yet to fully plan for these threats. “People oftentimes don’t want to have this discussion because it’s associated with an alarmist view of climate change, but it’s worthwhile to consider what catastrophic climate change would mean for habitable space,” says Michail Fragkias, an applied social scientist at Boise State University.

While the impact of many of these issues could lessen with proper planning, outside of a few progressive nations and cities, there is not much evidence that that is occurring. “No doubt the problems will work themselves out, one way or another,” Cohen says. “But likely at a cost of tremendous and avoidable human suffering.”

Cities, however, are not the only places that will experience future change due to growing populations. Rural and remote places that are not strictly protected will likely see a modest increase in human habitation, too. “With a combination of climate change and technology, it’s not unthinkable that Antarctica might become inhabited, although it’s hard to imagine it being densely populated,” Raftery says. This also means that, for those with the means to do so, finding a quiet corner free from humanity’s mark will become even more challenging. There will simply be too many other people with the same idea in mind.