The suddenly urgent quest to remove carbon dioxide from the air - The Washington Post: "“If you want to balance the books at this point, I don’t think you have a choice but to pull CO2 back that has already made it out,” Lackner said. “Or is about to make it out, because we are not overnight shutting down all the coal plants.”
But that turns out to be very hard to do. There are a wide variety of ideas for getting carbon out of the air — from little boxes like Lackner’s to specialized power plants that burn renewable biomass and stow the carbon away. But they all have costs and downsides — and they’re all part of a race to see whether any such technology can really be big enough, and cheap enough, to make a difference."