I used to think that the argument ' future technology will solve the problems' was a cop-out, a convenient excuse for not doing anything in the present. But it looks like different technologies really can replace fossil fuels. Being forced to build more dense cities and walk more would actually be an improvement I think.
even going back to using ships to cross oceans might not be all bad, the boat-trip that my parents took from New Zealand to England for New Zealand students going on their OE had the reputation of being a huge party boat and a great time!