It's possible to replace CFC with other gases. Just replace some of the F with Cl or something. It's not easy because CFC are incredible good at not reacting with anything. They are so good that they can survive all the way up to the upper atmosphere to cause havoc. If you replace the F by Cl or something you must do a lot of research to ensure the good properties in the new molecule version. So it's a problem that can be solved with research, time and money.

The problem with CO2 is that a lot of the energy requirements are solved by the equations:

  coal/petrol/gas + O2 --> CO2 + H2O + energy
  energy --> money

Or to simplify it

  whatever  --> CO2 + money

And it's not possible to replace the CO2 in that equation. No amount of money, time , research can fix this. You only try to use a completely different method to produce energy.

But most of the alternative methods are more expensive than a good old coal plant (if you ignore the social cost of pollution and the dangers of coal extraction). I think that nuclear and hydroelectric are cheaper, but they also have some hidden cost.