A good example is the imminent exhaustion of the world's inexpensive petroleum. Never again, perhaps, will so many people be able to move so easily, so cheaply or so swiftly. We may truly live in the Golden Age of mobility. And its end may be in sight. Alternatives to gasoline-powered internal combustion engines exist, to be sure.
Natural gas is likely to be our next major source of power for transportation.
But no known alternative provides both the cheap power and range of contemporary petroleum-based transport. Personal transportation based on any known alternative will, in general, provide shorter, slower, more costly drives. The jetliner, which has made the world so small, may go the way of the passenger pigeon, and the world may grow large again. It also may grow more urban as the suburban lifestyle of places like Los Angeles grows too expensive to maintain. And that's not even counting the effect of the end of cheap oil on the production of food, which is highly dependent on synthetic fertilizers made from petroleum products, or the skyrocketing price of transporting and refrigerating that food on its way to market.