My household’s carbon footprint is considerably lower than the national average. But my individual footprint is about double the national average. “Big whoop,” right?

Well, yes, if you figure lowering carbon emissions is essential to stopping global climate change.

The carbon footprint calculator at Eco Hatchery says I’m responsible for 22.6 tons of carbon being spewed into the atmosphere each year. Most of it comes from energy used at my house, and another big portion from the car I drive. The national average for a household is 30.9 tons, and for an individual it’s 11.9 tons, Eco Hatchery says.

This is all fine and good, but it doesn’t answer a basic question — what my carbon footprint should be. Someone whose carbon emissions are lower than the national average can feel good all day long, but maybe that same person needs to cut her emissions in half to be at a point where they’re low enough to help avert further global climate change.

I e-mailed the question to Eco Hatchery co-founder Andrea Nylund, and I’ll update the blog when she replies.

UPDATE: Eco Hatchery President Adam Borut called to explain why the calculator doesn’t set a target for individual carbon emissions. It’s a moving target, he says. The amount necessary for a sustainable environment changes all the time based on world population, shifting lifestyles and other factors. So any number the calculator asserts would be immediately out of date.

The better solution is for people and communities to set their own targets for reducing carbon emissions, Borut said. A lot of progress is possible with simple steps like improving house insulation and taking public transportation rather than driving a car, he said.

“I think it is a reasonable expectation without asking people to go bathe in a stream and sleep in a tent,” he said.

Borut admits some steps are more difficult than others, though. He said he’s able to take a train from Milwaukee to Chicago and cities on the East Coast, an option that’s not nearly so available to people in Colorado Springs. The Eco Hatchery Web site offers lots of ideas on small steps people can take to reduce their carbon footprints.