Sample Calcuation

Methane component

A typical beef cow:

• Produces about 500 lbs of meat
• Is alive for approximately 2 years before going to the slaughterhouse
• Produces approximately 114 kilograms of methane per year

That means that in a lifetime, a cow produces about 228 kilograms of methane!

1 kilogram of methane = 23 kilos of CO₂ (x 228kg of methane) = 5244 CO₂ equivalent over its life

A typical burger is ¼ lbs so 1 cow = 500lbs / (¼lbs) = 2000 burgers

5244 kilograms / 2000 burgers = 2.6 CO₂ equivalent kilograms from methane by flatulence and burping per burger

Energy Conversions

1 megajoule (MJ) = 0.278 kilowatt hours of electricity per MJ

In the Pacific Northwest with hydro electricity, on average 0.25 lbs/kwh of CO₂

Natural gas on average is 36.8 MJ/m³

1 m³ = 0.49 kg of carbon = 1.80 kg of CO₂ / m³

Example:

If you have 4.6MJ of energy of electricity per burger

4.6 MJ x 0.278kwh/MJ = 1.2788kwh (x 0.25 lbs/kwh) = 0.3197 lbs of CO₂ to get the amount in kilograms 0.3197lbs divide by 2.2

= 0.1453 kg of CO₂ per burger = 145.3 grams of CO₂ per burger

Example:

If you have 5.9 MJ of energy of natural gas per burger

5.9 MJ / 36.8 MJ/m³ = 0.160 m 3 x 1.80 kg CO₂ /m³

= 0.2886 kg of CO₂ per burger = 288.6 grams of CO₂ per burger

Diesel litre = 30 MJ

1 barrel = 158.9 litres

Diesel produces 10.1 kg of CO₂ emissions per gallon

1 gallon = 3.785 L

Diesel produces 2.67 kg of CO₂ emissions per litre

Example:

If you have 10.8 MJ of energy that is diesel per burger

10.8 MJ / 30 MJ/L = 0.36 L (x 2.67kg/L)

= 0.9612 kg of CO₂ per burger = 961.2 grams of CO₂ per burger

Downloadable PDF of this teaching aid.

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