Originally Posted by
YVR Cockroach
On the environmental cost, I agree. On the economic and/or energy cost, I suspect it will cost more than 100% of energy produced. The question is if the solar or whatever renewable energy can be put to better use.
But in a 100% renewable only economy of the 2050s there is no choice for the energy source. That might result in far higher energy prices.
And, as said (unless a miraculous battery or hydrogen storage technology emerges), jet fuel has the best energy density, so there is no choice for another propulsion source.
And an economy without aviation is also impossible (unless for shorter distances < 500km which might be replaced by high speed train or Hyperloop).