Well, that's not BAD, but you really would do more if you took up rice farming. According to recent research, the onset of irrigated rice farming in agriculture marked the REAL beginnings of global warming, and may, in fact, be the single factor that is keeping us from slipping into (or at least delayed) the onset of the next "Ice Age". It turns out that the bacteria in irrigated rice fields but out LOTS more methane per pound of "critter" than cattle.