We have all heard of the issue of the ‘farting’ cow, which tells us that the methane that is set free during the digestion process is extremely noxious to the environment. This is basically true. Nevertheless, the main pollutant is the amount of CO2 which is released in the production of animal feed and in the clearing of forests for plantations and pasture.
According to a Japanese study by Akifumi Ogino of the National Research Institute for Agriculture in Tsukuba 36 kg of CO2 are released in the production of 1 kg of beef. The respective amount of methane is included in this calculation. The global-warming-potential of methane is referred to in so-called CO2-equivalents, which means that 1 kg of methane corresponds to 25 kg of CO2.
However, if you include the fact that immense areas of rain forest are cleared for the supply of animal feed and for pasture land, the CO2 emission soars to 335 kg for one kilogram of beef. This has been proved by the Austrian scientist Kurt Schmidinger:
That corresponds approximately to the emissions of driving an average European car for more than 1,600 kilometers (1,000 miles). That means 1 single burger (0,5 lbs/200g) correspond to 200 miles/320km.
The rain forest is the world’s biggest reservoir of CO2. Nevertheless it is continuously cut down for
economic interest – despite climate change (cf. clearing of rain forest).