Biochar: UK tests refine carbon-capture solution

Biochar is being hailed as a possible "silver bullet" solution to climate change -- a form of charcoal formed by slow-cooking waste plant material that traps carbon for hundreds of years. But critics claim the environment could suffer if natural habitats are given over to biochar production. One small-scale experiment in England is looking to refine the art of cooking wood for maximum environmental benefit. Duration: 02:06