[adrianN]

The problem with any scheme to capture and store carbon from the atmosphere is the incredible amount of carbon we've blown into the air in the last 150 years. Just look at the size of the machines we use to harvest coal. Essentially you'd need to have machines of similar size working for many decades to re-bury the carbon we extracted and burned. Who's gonna pay for that?

[mr_toad]

There’s no getting around it. If we reduce CO2 emissions to zero it’s either plants or carbon capture, and one way or another the planet will have to do something with all that carbon.

Last time it took plants millions of years, and that was before things started eating wood. I’m pretty sure that we’ll have to have a hand in the process if we want to reduce CO2 levels in timespans shorter than geological.

[adrianN]

I agree that we’ll actively have to do something if we want to reduce carbon levels. I’m not convinced that we’ll want to reduce carbon levels badly enough to spent all that money. It’s very hard to convince voters that they’ll have to spent lots of taxes for a project that sees payoff in two or three generations at the earliest.