How's this for a thrifty idea? Build big greenhouses next to power plants. Take the carbon dioxide exhaust from a power plant and use it to grow plants you can eat. The natural carbon-fixing biochemistry of the plants turns waste gas into tomatoes. Oh, and someone's already doing it.
Even if you doubt the warming influence of CO2, that doesn't really matter here -- it's about making tomatoes from what would be thrown away even more than what the thrown away stuff would do once it's thrown away.
I don't know how much of a dent this actually makes in rising CO2 levels (probably not much really), and I'm not sure how the workers in the greenhouse are impacted by higher CO2 (it's probably low enough that they are unaffected). But it seems like a good idea overall. Let's close the carbon loop.