If there was no other way of generating electricity, then the answer is no.
If you can allow nuclear powerplants, then you will lessen use of coal.
If you can significant lower the cost of nuclear power, could completely get rid of coal use for electricity production [though you still will have coal use for making steel].

The Left has been engaged in a campaign [for decades] of increasing the cost of nuclear power. This is not a secret, they have proudly proclaimed this as one of the paths they are using to rid the world nuclear energy [and nuclear weapons].
This campaign has resulted in more coal use, and more CO2 put in the atmosphere [not to mention the increase of radioactive material from coal burning]. How effective this campaign has been is hard to quantify- though in terms scaring people [another path they have used] they have been quite effective. I think it fair to say that without the Left's entire effort against nuclear power, the US could easily now be in a similar situation as other modern countries- 80% or more of electrical power generation produced by Nuclear power or roughly 4 times the amount power generation from nuclear energy as we have today.
If we had this level of nuclear power generation, the reduction in total CO2 would more than total CO2 emission of all transportation CO2 emission.

Now, instead merely not trying to stop nuclear power plants, we effectively promoted and 1/2 the effort of stopping Nuclear was instead towards lowering their cost.
Then 90% of more of electrical power could come from nuclear power. We could have electricity cheap enough that home heating wouldn't need to use oil [another large source of CO2 emission]. Electrical cars would not only be better for the environment but they could as cheap or even cheaper than gasoline engines. And with today's electrical power capacity, if everyone suddenly decided to get electrical cars, it would create a shortage of electrical power [and at least in short term driving up electrical cost].

Now, I don't think nuclear power is only answer, but if we concerned about short term [20-40] then nuclear is a fast and cheap way to lowering CO2.

In terms of transportation, the internet, is already doing a lot to reduce the need for people to drive to work. There no reason this won't increase in the future- if for no other reason than the kids of today won't see any sense in "driving to work".