The possibility of carbon sequestration (the practice of pulling carbon dioxide from the air, either through technical means or through natural means, like growing more forests), is often used by those affiliated with carbon-creating industries as an argument for the continued use of dirty fuels (like coal). There are some potentially interesting wild cards in play, but great problems remain and so far the number don't pencil.

Mike Richard has done us all a service and pulled together some of the basics and major problems with using coal and relying on squestration in one post drawn from Tim Flannery's The Weather Makers. It's a smart overview.