I recently heard in the news that they were going to implement those changes very soon, how soon i cannot tell yet but i believe it would be great for the entire world if that could be done because we can all agree that most of the World's Pollution comes from China.
Converting billions of vehicles to electric would require millions of tons of Lithium and other rare metals. And I am not sure whether we have that much Lithium on earth (at least in deposits from which it can be extracted). Cobalt is another component of the electric car battery which is in short supply.