You don't need to worry about contributing to pollution.


Believe it or not, there are physiologists who have captured flatulence from humans and analyzed the gases. The principal contents of human flatulence are nitrogen (from swallowed air), carbon dioxide, and hydrogen. Both of the latter are from breakdown of food carbohydrates by the bacteria in our GI tracts. The odorous contents are hydrogen sulfide and organic sulfur compounds called mercaptans, from the breakdown of sulfur-containing proteins. They are present only in low levels (far less than 1% of the gases in flatulence), but they are what we notice, because they smell, and the other components are odorless.


None of these are significant contributors to air pollution. The concentration of the stinky sulfur compounds is too small to be an issue except in the immediate vicinity of someone who is passing gas - it's far, far less than that produced by the natural decay of organic matter in the environment. The carbon dioxide content of flatulence is far less than that of our exhaled air, so not a significant contributor to one's "carbon profile".

The flatulence of cattle and other ruminants is thought to contribute to global warming from its methane content. Ruminants produce methane because the bacteria in their more-complex digestive systems break down cellulose, forming methane as a byproduct. It's why cows can eat grass and hay. Human digestive systems can't do that, so we don't produce significant amounts of methane.

If I had to guess, I'd bet the taboo on human farting came from our hunter-gatherer days, as it could spook the tribe's dinner whilst your hunting group was sneaking up on it with spears.