^ While plenty of quality coal is still available, disreputable, or poor countries will continue to exploit it. Fracking for shale oil smacks of desperation to wean countries off Middle East supplies.

Perhaps not as many generations as you think?

Aircraft technologies for more efficient and cleaner power exist for a very good reason. Once the breakthrough occurs, economies of scale will make it available for air travel.

Not everything moves slowly enough for your dated philosophy to keep up.