Math! How much CH4 is released by Cattle/Beef Cow?

Math time again! 🙂

This time, I am set out to find how much CH4 is released by cow, or cattle around the world. Total cows/cattle in the world, according to FAO, in year 2003 is around 1 331 526 305. Note that this number does not include the dairy cow, or the cow for milking purpose.

Next, the quantity of CH4 gas emitted by a cow/cattle is searched. So far there are 2 claims, and may be more will be found in the future.

Claim#1:  according to wikipedia,

An average cow is thought to emit between 542 litres (if located in a barn) and 600 litres (if in a field) of methane per day through burping and flatulence, making commercially farmed cattle a major contributor to the greenhouse effect.

Let’s say the adult cow emits 550L of CH4 per day. Divide by standard volume molar (22.414 L/mol), the number of mole of CH4 is 24.538 mol.

Thus, the weight of CH4 = 24.538 x 0.016 kg = 0.3926 kg per day.

Or, 143.3 kg CH4 per year.

Claim#2: according to US Enviromental Protection Agency,

An adult cow … emitting only 80-110 kg of methane (annually).

It is noted that claim#1 is almost 43% higher than claim#2, if the value of 100kg per year is assumed.

Therefore, total CH4 released by cattle/cow annually in weight for year 2003 is:

Claim#1: Total CH4 = 143.3 x 1 331 526 305 = 190.81 x 10^9 kg = 190.81 million tonnes.

Claim#2: Total CH4 = 100 x 1 331 526 305 = 133.15 x 10^9 kg = 133.15 million tonnes.

More livestock’s impact on environment can be read from UN’s news release and the report.

source: FAO, Global Livestock Production and Health Atlas.

1 Comment

  1. April 10, 2007 at 7:07 am

    […] Environment) More CH4 emission by cattle or beef cow is found! Thefore, I shall continue from the previous post from […]


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