Tame Your Home's Energy Hog

You know what a carbon footprint is -- a measurement of greenhouse gases emitted as a result of human activities -- and you know that a smaller carbon footprint is better for the environment. You even know that you can reduce your carbon footprint by flying less, buying local products and driving a fuel-efficient car.

But your carbon footprint isn't based solely on your travel and shopping habits. If you're like most people, about 40% of your carbon footprint comes from your home. Shrinking your home's carbon footprint has the added benefit of reducing home energy use (and costs). Expect to knock at least $100 off your annual electricity expenses just by making a few small changes -- and if you go whole hog (see below), your next electric bill could be zero. So how do you reduce the carbon footprint of your house?

Step one ...