It would be no more than a small step in fighting climate change, but what if Utah became the first state to outlaw the gasoline automobile?
If the experiment worked, other states would follow.
You would have to do it incrementally, for you have to keep the automobile affordable, and you probably shouldn't require people to go out and buy new cars. So, start with new vehicles. Prohibit any new automobiles from being bought or brought into the state. Then, prohibit any sales of gasoline cars (even if they might be old cars) and prohibit buying any car out of state and bringing it into Utah. Then -- third step -- prohibit any use of gasoline vehicles at all.
Remember the prohibition of alcohol? You were were probably about to bring that up. With prohibitions, come black markets and underground sales and pride that swells for having beat the system and beat the government.
So, offer no punishment for those who break the law. Take away their glory. Hopefully, this would leave the person breaking the law to be shamed. When you do that which hurts society, there can be a shame. When you do not support that which is best for the whole of society, there is a shame. There might reach a point when most everyone is on-board, and at that point, you might institute penalties, but not before.