[cryptoz]

The economies of scale in electricity production are immense, so yes it is indeed an improvement to move to electric cars even if all electric cars are fed by dirty pollutants. Which they aren't.

Also, a move to a less polluting industry is more than the sum of the direct effects; you must also consider research and momentum - as more electric cars are built, solar power and battery efficiency will also improve. If you take the opinion that an electric car is the same as a gas car because at some point they both pollute, you'll never make any progress anywhere.