The great charcoal debate

George Monbiot kicked the debate off on Tuesday, arguing that there is insufficient land worldwide for charcoal, or 'biochar', to serve as a global solution to climate change.

Chris Goodall responded to Monbiot's criticism the same day, pointing out that soil dosed with charcoal can improve agricultural productivity, reduce the emission of other greenhouse gases from soil and improve the effectiveness of artificial fertilisers.

James Lovelock replied later, agreeing with Monbiot that it would be "wrong to plant anything specifically to make charcoal" and that "we don't need plantations or crops planted for biochar."  However, he went on to suggest that if farms were equipped with 'charcoal makers', wastes from crops like wheat and rice could be used to make carbon-sequestering charcoal.

Goodall mentions a book that will be published next month - Johann Lehmann and Stephen Joseph's Biochar for Environmental Management - that should provide some thorough research on the subject.

UPDATE: James Hansen and Pushker Kharecha weigh in on the debate here. The two NASA scientists reject the notion that they ever considered biochar to be a "miracle cure", and state that there are "hundreds of millions of acres of suitable, sparesely inhabited lands" that might be suitable for re-afforestation.