After watching an episode of top gear, where Mr. Clarkson proclaimed that cows produced more harmful greenhouse gases than cars and should be banned or a carbon tax imposed, I decided to do some research to find out the "truth" about the car versus car battle of the Methane Gas. The first strange fact was that it wasn't farting cows that were the problem it was their bad breath. Cows produced 80% of their methane production from their breathing rather than their farts.
The Maths and Statistics Bit:
I tracked down some facts and figures. The average petrol car produces about 20 pounds of carbon dioxide per gallon, say at a very good 40 mpg and an average 10,000 miles per year, each car produces 10,000/40x20= 4100 pounds of carbon dioxide.
The average cow is said to produce 100 kilogram's of methane per year, although figures varied wildly depending on the studies I went for a mid range estimate. So converting kilo's to pounds 100 x 2.2 = 220 pounds of methane is produced by the average cow.
Then how do we equate methane as a pollutant to carbon dioxide, is this apples and oranges. Well after further research it appears that studies indicate that methane is 20 times more harmful as a greenhouse gas than carbon dioxide.
Therefore the average car produces 4100 pounds of greenhouse contaminant per year and the average cow produces 4400 pounds of greenhouse gas contaminant per year.
Conclusion:
Cows and cars probably produce similar amounts of greenhouse gas contaminants per year. However estimates of the number of cars in the world vary from 5-600m and the number of cows are estimated at 1.5bn so the conclusion has to be that cows are more harmful to the environment than cars.
Serious research is underway to try to tackle the problem. A Welsh University is looking at garlic to neutralise the gas in the cows stomachs, they have 4. In New Zealand they were going to introduce a flatulence tax. Recent research by an Irish University is trying to identify the causes and modify the cows diet to reduce the harmful emissions.
