On the hoof
Do cows and other domestic-herd animals really emit more methane than bison and other wild-herd animals emitted before people came along? Do grass, alfalfa, and other pasture plants remove less carbon dioxide than do forests? There were open grasslands before pastures replaced some forests. I hope the people who are researching these things ("Big footprints," SN: 1/13/07, p. 30) take such issues into consideration before trying to frighten everyone into becoming vegetarians.
Not only is the finding that nanotubes "remained in particular in the liver and spleen" of concern ("Tracking nanotubes in mice," SN: 1/27/07, p. 61), but there is no indication made or concern expressed over what happens after excretion. What biological activity do these structures have in the open environment, and for how lon