Without atmospheric carbon dioxide, life as we know it would not be possible.
Without atmospheric carbon dioxide, life as we know it would not be possible.
−
All carbon in protein, fat, carbohydrate, and the other organic molecules in living things is derived from atmospheric carbon dioxide. [http://hypsithermal.wordpress.com/2008/08/31/assault-on-reason-by-expert-al-gore/]
+
All carbon in protein, fat, carbohydrate, and the other organic molecules in living things is derived from atmospheric carbon dioxide.<ref> [http://hypsithermal.wordpress.com/2008/08/31/assault-on-reason-by-expert-al-gore/ Assault on Reason, by Expert Al Gore] - Global Warming: A Worn-Out Hoax</ref>