What would happen if the US and the EU both decided to ban the sale of new gasoline-powered vehicles as of a future date about twelve to fifteen years in the future, say 2020 for instance? That ought to give automakers plenty of time to adjust and it wouldn’t place any limitations on vehicles already on the road prior to that date.
Norway has already been considering banning gas vehicles, although the Norwegians are apparently thinking of switching to ethanol whereas it seems to me that electric vehicles would probably be preferable.
A future ban would be a great spur to technological innovation and would make an enormous contribution to both energy independence and the environment. It would be an example for China and India and the rest of the world too.
There are two principle drawbacks to replacing gas with electric: the energy for the electricity has to come from somewhere and the range of current electric vehicles is too short. The first objection is really just one aspect of the great general question of where we should get our power from in the future and there are obviously several answers (solar, wind, nuclear, “clean” coal, etc.). The range of electric vehicles is constantly improving: lithium-ion batteries should bring the distance up to 250 or 300 miles. There is also the option of using battery-exchange stations for long trips.
Distance is obviously a much smaller problem in limited areas like Hawaii. Big cities are another special case. Here are a couple of guys testing out electric vehicles in London. The cars shown are a bit unsafe and unsexy, but they’re fun:
For more information on environmentally friendly vehicles, read AutoblogGreen - a fascinating blog that is frequently updated.