This is why carbon retrieved from 300m years of sequestration will be so hard to remove from the atmosphere. It’s because, when it was locked away, there was no way for plant fibers to decay, so sequestration was super-efficient. Today, plants can decay, so the carbon will keep cycling and removal will be through much slower processes.
(Note: I think the briquette shown at the beginning is a compressed coal-dust briquette, a type we don’t see much here in the ‘states)
georgewiman 