Per the American Heritage Science Dictionary, carbon is "a naturally abundant, nonmetallic element that occurs in all organic compounds and can be found in all known forms of life." Many politicians and journalists refer to carbon dioxide, a greenhouse gas, as "carbon." This is both unscientific and misleading. Unlike carbon, carbon dioxide is colorless, odorless, and nontoxic at many times the concentration in earth's atmosphere. Referring to carbon dioxide (CO2) as "carbon" is like calling H2O (water) "hydrogen."