Replace your lightbulbs with CFLs and LEDs

I know you're heard this one over and over, but have you done it? Compact fluorescent lights (CFLs) use 50%- 80% less energy than incandescent bulbs and last up to ten times longer.  Light emitting diodes (LEDs) do not contain mercury and have 60,000 hours of useful life. Replacing a single incandescent bulb with a CFL will keep a half ton of CO2 out of the atmosphere over the life of the bulb.

There are CFLs or LEDs for different types of lights, including soft and bright lights as well as for dimmers, so read the label carefully to make sure you are buying one that is appropriate for your needs and your budget. In addition, for spaces where you will only be using the light for a minute or so (ex: your closet), consider getting an LED or sticking to incandescents, at least for now. In order for CFLs to work properly, they need to be left on for at least 15 minutes (different studies will show varying times, but 15 minutes is a good yardstick). If they burn for less than that amount of time, they will not last as long as they are designed to.