Put a cork in it! The average dairy cows burps and farts out between 100-500 litres of methane gas. This is equal to the pollution produced by a car in a day. Showing that by farming cows for diary products like milk, cheese and butter contributes to the amount of greenhouse gases, which in turn increases global warming. Click here to read more at www.science.howstuffworks.com Vinyl by David Mapp from Marry Webb School & Science College. Big up! 2011.