The methane and carbon monoxide released during charcoal production have short atmospheric lifetimes compared with that of fossil fuel carbon dioxide. In the long run, the net effect of charcoal on the climate is nil because the wood used to produce charcoal was formed from carbon dioxide by photosynthesis. Recommending that nations convert from charcoal to propane is thus shortsighted.

Lee R. Kump
University Park, Pa.

Two coauthors of the research say their team’s analyses show that even after 500 years burning charcoal has a stronger warming effect on Earth’s climate than burning a comparable amount of fossil fuel for cooking, unless the very best charcoal kilns and charcoal stoves are used. –S. Perkins