CO2 data from here: http://www.miloslick.com/EnergyLogger_files/State_Electricit...
It looks like there isn't any state where driving an electric actually produces more CO2 than driving a gas car. And that's before you include the CO2 generated from refining oil (which requires a fair amount of electricity).
Edit: Assumption is stated as 22mpg at the bottom of the page.
That's fair if you are comparing the Model S to a similar luxury car. It also means the Prius wins in a lot of states.
That's true. But I think Tesla is trying to sell the Model S to people who would otherwise buy a similar luxury car. There are a not-insignificant number of people in the world who just hate the Prius because it sacrifices handling, performance, and interior finish for the sake of fuel-efficiency. If Tesla builds and sells a car that those people like, isn't it still a net win? People who like hybrid Priuses can still buy them.
It's good that one half of the puzzle is mostly complete, as the electric car seems to be here for good. I think moving energy sources away from coal will be the more difficult and time consuming task.
That's much harder to do for the car, because you only have a limited budget for space and weight to attach things to the car.
FTFY
Assuming he drove a gas powered Honda civic instead he would have burned 375 gallons of gasoline (12000 / 32 combined MPG).
One ton of coal releases 2.86 tons of C02. One gallon of gasoline releases 19.64 pounds of C02.
Driving the electric vechile released 5.022 tons of C02.
Driving the gas civic would have released 3.68 tons of C02.
All numbers shamelessly cribbed from whatever google result seemed nice.