The following is a small excerpt from Chapter 11 of Stop Feeding Us Lies.
“Grass grows by taking CO2 out of the air. With the help of energy from sunshine and water from rainfall, grass converts atmospheric CO2 into molecules of carbon, hydrogen and oxygen. Some of these carbohydrate molecules, called cellulose, are used to create new blades of grass and some, which are more simple sugars, are passed down the plant and into the roots. To keep the arithmetic simple let’s assume a blade of grass absorbs 100 molecules of CO2 and that 80 of them are used for growth and 20 of those carbon atoms go down to the roots, where they will stay if the ground is left undisturbed.
Constance the cow comes along and eats all of those 80 carbon atoms in the grass. The bacteria in her rumen get to work and convert plant cellulose into the fatty acids and proteins that Constance needs to grow. A by-product of this process is methane gas which is produced at a rate of approximately 5% of the food Constance eats. Therefore for every 100 molecules of CO2 absorbed by grass, cows return 4 or 5 of them to the air as methane. Simple arithmetic and basic biology show it is impossible for cows, or sheep, to add greenhouse gases to the atmosphere. They simply recycle a few of them.”