In an earlier blog (23 Feb 2011) I mentioned that by eating fibre containing foods you would become a methane producer and therefore, to a mild degree, be contributing to global warming along with the cows.
As commonly happens, I then came across another paper that explained that only one in three people are digestive methane producers (American Journal of Gastroenterology 2010; 105: 1250-1256). Have a look at the person either side of you. One of you is a methane producer.
It also appears that in many cases the production of methane is linked to irritable bowel disease and colon cancer. Abnormal levels of methane could signal that you are unwell, or about to become so. Now, just take a closer look at the person either side of you and hope that one of them looks less healthy than you.