To reduce transportation emissions worldwide, there needs to be greater emphasis on alternative modes of transports to cars, electric or not.
- Long distances should be covered by train/bus.
- Medium distances by metro/bus/tram/whatever works in a given city’s geography and layout.
- short distances by cycling/walking.
- an EV when you need the flexibility of a car.
One issue with EVs is that they aren't necessarily a feasible option for a lot of households due to their cost. Putting a market incentive in place would lead to a hundred different ways of reducing our CO2 emissions from driving, not limited by the ingenuity of one person or organization. More people working from home, more carpooling, distributed co-working spaces, more use of public transportation, even shifting how we design and zone our towns and cities, are a few things I can think of.
I strongly recommend that anyone who wants to take a very direct, immediate, simple action to move the USA toward having a carbon fee and dividend policy* take a look at this (or at the very least, send it to your environmentally concerned friends and family): https://citizensclimatelobby.org/senate/
(*a tax on carbon, where, that get returned to all citizens so as to reduce or even eliminate impact on lower income families)
Beyond that, cap-and-trade scheme has worked to reduce SO2 emissions and it will work to reduce CO2 emissions.