National Geographic recently released an article entitled "Dinosaurs' Gaseous Emissions Warmed Earth?" (Published May 7 by Charles Choi on NationalGeographic.com) in which it describes and critiques the findings of a study done by Dr. Dave Wilkinson of Liverpool John Moores University. The jist of the article is if modern day lizards and mammals give off 50-100 million metric tons of methane gas annually then 20-ton dinosaurs probably gave off somewhere close to the total amount of current natural as well as man-made daily emissions, which is around 520 million metric tons annually. And, while the comments left by readers of the article indicate a bit of debate and skepticism, I believe the results are simply a reflection on how much we know and don't know about the earth and its geological and environmental history.
Really, this is just more proof that warming and cooling are all a part of the natural cycle of things. "...fossil findings make it clear that sauropods lived in a much warmer world than we do. People sometimes describe it as a super-greenhouse." Haha, yeah, a super-greenhouse of dino farts!