I posted earlier about my first carbon-footprint calculation attempt, on carbonfootprint.com and thought I’d try another couple calculators to see how they compared.

First, I tried The Nature Conservancy‘s calculator. They gather a lot less detailed information than carbonfootprint.com, but also ask some new questions, like how often I check my truck’s air filter and tire pressure. They also have a way to be clear that I’m getting my individual carbon footprint, not that of my household, which was not so clear with carbonfootprint.com. They calculated my carbon footprint as much bigger than carbonfootprint.com, though, at 17 metric tons of CO2 per year: 17.8% on home energy, 64.6% on driving and flying, 2.8% on waste and recycling, and 14.9% on food and diet.

They also provide an opportunity to offset my entire carbon footprint and calculated the cost for me to do was $255: $15 per metric ton. That’s pretty cheap. I’ll have to look into carbon offset schemes and see if they are convincing.

Second, I tried footprintnetwork.org. They try to calculate how many planet earths it would take to support a population living my lifestyle–an interesting way of thinking about it. They gather a lot of the same information as the other sites, like how local is my food and how much I fly and drive. In some areas they gather more details, like how often I eat each of several kinds of animal products, how often I buy new clothes, furniture, appliances, and computer gear, and what kind of siding my house has.

This site estimates that if everyone lived like I do, we would need 3.5 planet Earths to sustain us. They suggested several ideas that would decrease my footprint: .1 of an Earth if I half my animal product consumption, .2 of an Earth if I “pledge to use less packaging,” .1 of an Earth if I use public transportation once a week, and .1 of an Earth if I do not fly this year because I chose “a local vacation.”

If I did all of these things we would need only three Earths to sustain us all at my standard of living. Half of an Earth’s savings is nothing to scoff at, but doesn’t really get us there. Plus, I already use very little packaging, and do not often fly for vacations.

They estimate how many “global acres of the Earth’s productive area” my lifestyle requires:  7 acres “energy land,” 2 acres “crop land,” 1 acre “grazing land,” 2.5 acres “forest land,” .5 acres “built up land,” and .25 acres “fishing grounds.”

They also calculate my “ecological footprint” percent by category: 52% in services, 11% in goods, 12% in mobility, 4% in shelter, and 16% in food.

Something is wrong about these calculations, but I’d need more details to know what. Half of my land-use is for energy, but half of my footprint is in “services.” What are these services that are using so much energy?

Still, a picture emerges. I have estimates of 10.41, 13.7, and 17 metric tons of CO2 per year, approximately 3-5 times as much as an ethical target. I probably create the most CO2 by burning fuel, driving and flying.