It's also very important to remember that there are many good reasons for weaning ourselves off of fossil fuels even if CO2 wasn't an issue.

The sooner we start building more nuclear plants, the better. The transportation systems are going to start moving away from internal combustion, and it would be nice to get a head start on it.

I have no idea if electric transportation off of fossil-fuel plants results in more or less CO2 in the air (it does result in less of other kinds of pollution). There are factors pushing in both directions, but my gut tells me (for whatever that's worth) that there might be.