Burning “biomass”—trees, grasses, and other plant matter—to generate electricity has been considered a “clean” technology in some quarters. Currently, European countries do not count carbon dioxide emitted from biomass burning as part of their greenhouse gas (GHG) emissions. This is curious, given that burning biomass does emit carbon dioxide, as well as a small amount of methane. How renewable is biomass burning? Does it leave a “carbon debt” of carbon dioxide in the atmosphere?