On a challenge from the blog 400 Days ’til 40 I did a quick-and-dirty calculation of our carbon footprint for a year here in California. I just used the top hit on Google for “carbon footprint calculator” and made my best estimates for all the values they asked for:

1. I live in California, USA, in a household of two.

2. I use no natural gas, heating oil, coal, LPG, and no net electricity by virtue of a solar array, thanks to an investment by my father. Reanna and I cook with propane, and a little research is leading me to believe we will go through approximately 50 gallons in a year, maybe less. Our share of the firewood that my parents burn for heat in the evenings is about .4 of a cord. My share of all this contributes .08 metric tons of CO2 per year.

3. I fly to Portland and to Albany every year to work at Not Back to School Camp. That contributes .95 metric tons of CO2. Something like a quarter of a ton for each leg. Pricey!

4. Car travel is the biggest polluter at 5.05 metric tons of CO2. This amount probably varies quite a bit each year and is way up from my Eugene, OR lifestyle. This estimate includes a few trips to town each week, a dozen trips to the LA area, and one long road trip to Canada. That’s a bit less than 2 tons for each of those kinds of commutes.

5. I use a significant amount of bus and train travel on my business (and some other) trips as well, adding about .12 metric tons of CO2.

6. The second biggest polluter is a group of “lifestyle” choices. 1.21 tons for eating animal products, 1 ton for owning one car, .5 tons for eating only “mostly” local produce, .61 tons for buying stuff with packaging, .17 tons for buying “some” new equipment, .41 for throwing some stuff away, 1 ton for sometimes going out to movies and restaurants, and .4 tons for having a bank account. Total = 4.21 metric tons of CO2. (The highest value possible here was 24.53 tons.)

Here is the summary they gave me:

  • Your footprint is 10.41 metric tons per year
  • The average footprint for people in United States is 20.40 metric tons
  • The average for the industrial nations is about 11 metric tons
  • The average worldwide carbon footprint is about 4 metric tons
  • The worldwide target to combat climate change is 2 metric tons

I have plenty of questions about and criticisms of the way this calculator works. They ask my household size first but do not indicate if they are calculating my individual footprint or my household’s. That could change my score quite a bit if I’m taking the blame for Reanna’s share.

I’d like find a calculator which takes into account more specifics, too. I have owned the same car for 20 years, for example, but the way they asked the question gave me the same carbon footprint as someone who has a brand new SUV every year. Miles driven, too, is not as important as number of gallons of gasoline burned (see my mileage/fuel tracking project here). I buy some things with packaging and I throw some stuff in the landfill (see my landfill tracking project here), but “some” is a vague category to hang such a precise 1.02 metric tons of carbon on! What about grass-fed versus industrially produced meat?

On the other hand, two metric tons is a pretty tight carbon budget, and finding a more accurate calculator will not likely shift my score dramatically. And with this calculator, I am at 520% of my two metric tons, this with a relatively low-profile lifestyle for an American. I could come down to 222% if I did not own a car and never drove one. If I also stopped eating animal products and stopped going to movies and restaurants, I would be close, at 112%. If I also stopped flying, I could actually come in under budget, at 64%, leaving some slack for others.

That’s a pretty discouraging proposition! The biggest barrier is the isolation. No travel means never seeing a large part of my family and community. And the idea is that kinds of lifestyle choices would have to become the norm, not just the domain of eccentrics….

I’m going to have to do some more thinking about this.