Every individual has a carbon footprint, as does every household; that is, the amount of carbon dioxide and other emissions produced by our daily actions that contribute to global warming. Many decisions we make have an associated carbon value—whether we commute by train or car; use fans or air conditioning; how long we shower; and how often we wash clothes.

According to the U.S. Department of Energy (DOE), a typical U.S. home uses 11,000 kilowatt-hours (kWh) of electricity a year. Unless our household is powered by renewable energies, every single kWh we use requires the burning of 3 kWh of fossil fuels, like coal, at a power plant. The use of such conventional fuel emits carbon dioxide, sulfur dioxide and other toxins, such as mercury and lead, all of which contaminate our air, oceans, food chains and drinking water.

“If you use less energy,” says DOE spokesperson Chris Kielich, “there’s less demand on power companies, which means fewer new coal plants.”

Free online calculators provide a helpful tool to get a handle on our current carbon footprint. Easy-to-use websites include SafeClimate.net/calculator, www.CoolClimate.Berkeley.edu and www.Nature.org/calculator.

When it comes to a family’s energy use, the biggest piece of the pie is heating and cooling. According to data from the latest Buildings Energy Data Book, space heating accounts for 31 percent of the average family’s energy use, and cooling 12 percent. Figure in the additional 12 percent it takes to heat household water, and that’s a whopping 55 percent of our total home energy consumption, just for heating and cooling needs—collectively representing 46 percent of annual utility bills. Rounding out our expenditures, lighting generally accounts for 11 percent of our energy use; computers and electronics, 9 percent; refrigerators, 8 percent; and various other appliances, 8 percent. The remaining 8 percent falls under “other.”

The DOE recommends starting an improvement campaign with a home energy audit, whether we do it ourselves or in collaboration with a professional. Be on the lookout for proper insulation levels and any air leaks, cracks or spaces around doors, window frames and electrical outlets, all common sources of heat loss. The EnergySavers.gov website walks inquirers through the process—just search under “audit.”

After determining needed improvements, take a whole-house approach to energy savings. For instance, buying an energy-efficient furnace, while it reduces emissions, will have a much greater impact when combined with proper air sealing and insulation, better ventilation and adjusted thermostat settings. When all such actions are taken into account, notes the DOE’s Energy Savers Booklet, we can reduce our family’s environmental emissions by 20 to 50 percent.

The first efficiency update a homeowner needs, advises Kielich, is a programmable thermostat. For about $35, a family can easily realize savings of 10 percent off their energy bills by simply lowering their heating settings or raising their cooling settings by 10 degrees for eight hours during the day. Another easy energy- and money-saving tip she recommends is replacing all home light bulbs with compact fluorescent bulbs (CFL).

“CFLs are hugely more efficient, and they also produce less heat,” Kielich says, so the air conditioner doesn’t have to work as hard during warmer months. According to research by the Rocky Mountain Institute (RMI), CFLs are four times as efficient as incandescent light bulbs and last 10 times as long. Over their lifecycle, reports RMI, they’ll save 75 percent of greenhouse gas emissions over conventional lights.

Starting with more manageable tasks helps families adjust gradually to a greener lifestyle. Soon, we witness first-hand how little actions—such as turning off lights, shutting doors and shortening showers—can have a big collective impact.

For more information visit: Department of Energy, EnergySavers.gov; and Rocky Mountain Institute, search “CFLs” at www.RMI.org.

Brita Belli is the editor of E/The Environmental Magazine and author of The Complete Idiot’s Guide to Renewable Energy for Your Home. Connect at [email protected].