Is that another scheme similar to corn ethanol? Sequestration of carbon by putting more carbon into the atmosphere?
Yes, biochar is a stable form of carbon which can be stored for long period of time AND is produced from biomass. If Treehugger's title (Carbonscape: Microwaved Biochar for Massive Carbon Sequestration) suggests how it would be done, I would totally object it. There are much better way of converting biomass into biochar AND energy, see Carbon Negative Energy Source.