I’ve been trying to ride my bicycle into work at least once a
week now that the weather is agreeable. My main goal is to get in shape for the
Kirkwood Triathlon, but it struck me on one of my rides that it could
also be a potential way to get some of that sweet, sweet carbon offset money.
And since I just read a book on carbon footprints, I thought I’d figure
out what my commute by bike might be worth.
Since this is America, I’ve provided the carbon footprint
equivalents in pounds versus grams or kilograms.
1.9 lbs/mile driving a standard sized car
9.8 lbs/mile driving a standard sized car in congested
traffic
But let’s assume a little of both, so I’m going to split the
difference:
5.85 lbs/mile driving a standard sized car on average
When it comes to cycling, the author provides a range of
different food (power) sources. I eat yogurt in the morning, so this was the
closest comparison.
0.2 lbs/mile riding a bike powered by cereals with milk
My commute is approximately 14 miles round trip. So when I
drive, my output is 81.9 lbs total (5.85 X 14). When I ride my bike, my output
is 2.8 lbs total (0.2 X 14).
A ton is 2000 lbs and the maximum equivalent price per ton
of carbon in the UK (the figure cited in the book) is $18.
So I will reach a total of one ton of carbon roughly every
24.5 times I commute by car (2000 ÷ 81.9). On the other hand, it takes me
approximately 714 trips to reach a ton of carbon by bike (2000 ÷
2.8).
That’s a ratio of roughly 29:1 (81.9:2.8). So commuting by bicycle
twenty nine times has the same carbon footprint equivalent as one trip by car.
Put another way, by riding my bike I use up only 2.8 lbs of
my normal 81.9 lbs, leaving a surplus of 79.1 lbs/commute. By dividing 2000 by
79.1, the total comes out to be about 25.5 times, which, as I’ve pointed out
above, is the approximate equivalent of 24.5 car trips, or one ton of carbon. So,
more accurately, 25.5 bike rides equal 24.5 car trips—basically, one bike ride
by me offsets one car trip by you (assuming an equidistant commute). And since
one ton of carbon is worth about $18, I figure if you want to ease your conscience,
you can pay me $17 in carbon offsets (to account for the difference in ratio) every
time I ride my bike and you decide to drive.
Please make checks out to That Tad Guy.
*It’s been awhile since I’ve used the old math muscles, so
my apologies if any of these numbers are off or inaccurate.
