• Your also going to run into the Pasific and Atlantic pretty soon. Most people who live in Hawaii for instance probably arn’t going to be very happy spending two weeks in the middle of the ocean when they want to visit their kids who went off to college on the mainland. Combine with the fact that while more efficient ships also need fuel and produce carbon, and I don’t think it would make enough of impact to be worth the cost.

      A proper high speed rail network would help eliminate some shorter flights, as would a bunch of regional rail, but I feel like flying is one place where the high cost and limited supply of carbon capture produced synthetic fuels might actually be the most effective answer. Limit flights to trips between hubs more than a thousand miles apart or so, or which can’t get a practical rail connection.

      The other main thing that your going to run into is that the airline network is the only real intercity public transport system in north america. For a lot of smaller towns, especially in the West and Northwest, the once daily puddle jumper is the pubic transport to speak of, and flying for thirty minutes to an hour or two is always going to compare favorably to a four to six hour drive to get to the city.