Saving the Planet Two Wheels at a Time

Since I started commuting by bike (most days) I’ve cut my gasoline consumption dramatically.  How much.  Let’s get geeked out.

My truck (4 banger Toyota) has about a 14 gallon tank.  I fill this once a month now (at most) which is roughly a third of my previous refill visits.  So, for arguement sake, I am saving 9 gallons of gas a month.

What does that mean to the atmosphere and greenhouse warming potential?

Some math…

Heat yield of gasoline = 5.5 x 10^3 megajoule (MJ) / barrel of gasoline

[interesting factoid ~ biomass (vegetation) heat yield is about 18 MJ / kg of fuel.  No wonder we burn the black gold instead of wood chips.]

The carbon coefficient for gasoline is 18.34 grams of carbon (C) per MJ (i.e. how much C released per MJ of gasoline burned)

This yields about 100,000 grams of C per barrel of gasoline.  Convert barrels to gallons to get a real world number (42 gallons in 1 barrel)

So 0.02 * 100K of C = 2,400 grams of carbon per gallon.

But carbon is not widely used in climate assessments so we’ll convert this to CO2.

Molecular weight of Carbon = 12 g.  Molecular weight of Oxygen = 16.  Thus CO2 molecular weight is 44 g.

Convert C to CO2 (44/12) = 3.67 and multiply by 2,400 = 8,810 g of CO2 per gallon OR 8.8 kg per gallon.

8.8 kg * 9 gallons less per month =  79.2 kg of CO2 less emission per month.

This is equal to 0.08 metric tons of CO2 / month (1000 kg = 1 metric ton = 2205 lbs or 1.1 U.S. ton).

So in a 12 months I will have reduced my CO2 emissions by 1 metric ton (12*0.08) or roughly 2200 lbs.

For reference, this is half the weight of my truck less CO2 emitted each year to the atmosphere.

Your Welcome.


~ by Indy on February 20, 2009.

2 Responses to “Saving the Planet Two Wheels at a Time”

  1. u lost me at ‘Some Math’.

  2. Ask Steph to see the shirt I got her when I ordered that batch from Busted Tees. I’d rather not repeat the phrase in this forum.

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