> I wonder how much this will last considering that fossil energy will likely cost more and more and that more and more people from developing countries start t

> I wonder how much this will last considering that fossil energy will likely cost more and more and that more and more people from developing countries start to travel too. Actually I think the cost of fuel to fly a passenger from New York to London will be cheaper in 30 years, for two reasons: (a) Motor vehicles will no longer be powered by gasoline; and (B) planes will continue to become more fuel efficient.