Reduce Your Carbon Footprint With Carbon Credits

Sarah Warren considers herself an "unlikely environmentalist": someone who a few years ago would only casually recycle her garbage but who now can tell you her home's carbon footprint. That happened after Warren, a psychologist in Evanston, Ill., realized how environmental degradation poses "a clear threat to the health and well-being of my children," she says. After that, Warren switched from incandescent to compact fluorescent lightbulbs, vigilantly turned off lights, installed a ceiling fan to reduce air-conditioning costs and eventually used a new tool to green her home: buying carbon offsets after measuring the extent of her home's carbon footprint.

A growing number of eco-conscious homeowners are doing the same, as part of an effort to not only help the environment but also reduce energy use and utility bills. Supporters of carbon offsets (also called carbon credits) say that it is an easy way for individuals to make a difference on a small scale in reducing global warming, although some critics argue that offsets don't always accomplish that goal.

Carbon offsets can be confusing, like the heated debate over climate change itself. So here's what you need to know if you are considering joining the offset movement: