Chewing the cud yields enormous amounts of flammable methane that should, in theory, make cattle more vulnerable to unexpected ignition than people. Carbon dioxide emissions hang around for over a hundred years.
Atmospheric methane breaks down within a decade.
So, reducing methane emissions will have a more immediate impact on global warming. Power stations, coal mining and even growing rice generate methane but up to a fifth of all 'man-made' emissions originate down on the farm. Bacteria in the stomachs of cows break down and ferment fodder during digestion, producing methane. Such emission estimates have been made before but Kaharabata believes these are the most accurate so far. He believes the answer is optimizing dairy farming so cattle produce as little methane as possible.