In the same line that the government moved to extinguish the threat posed by the common lightbulb, lets say that having so many forms combustion tied to oil was seen as globally unstable. So new law, in 20 years you will not be able to buy petroleum fuels. You can still buy them for lubrication and other purposes but gone will be the gas station gas pumps and home heating oil tanks, gone also are the white gas camping stove fuels. Even military vehicles must run primarily on non-oil fuels (but can if it is a emergency with mulitfuel engines).
20 years seems like the time frame to make this conversion, primarily to build new power plants, perhaps nuke ones to pick up the slack once more electric vehicles will be hitting the road. Natural gas also expected to be a major player. Bio-fuels will pick up the stragglers still looking for some liquid fuel to burn, and might make some major breakthru’s.
Cars in the near future, well gas will still work as that is 20 years down the road till you can’t get that anymore, and conversion to flex fuels, to be able to use bio fuels in case the car you buy today lasts the 20 years and still be able to fuel it seem like a cheap fix for today.
How would such a thing play out? Does it go smoothly? Does carbon intense coal add much more CO2 to the air melt the icecaps and give penguins the best real estate on the planet?