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The electricity we generate is responsible for 38 percent of carbon dioxide emissions in the United States, making it the largest single source overall. As demand for electricity has risen, so have greenhouse-gas emissions, increasing by 25 percent over the last two decades, according to the Pew Center on Global Climate Change. That's because most of our electrical-power supply comes from burning fossil fuels—natural gas, oil, and, especially, coal, a huge CO 2 culprit.
Coal is abundant and relatively inexpensive, so it's likely to remain a prime source for electricity for decades to come. And with operation costs on the rise, power companies aren't likely to invest voluntarily in technologies to reduce emissions. There are low-carbon options: Renewable power sources such as biomass, wind, and solar currently account for just 0.6 percent of electricity production. Hydroelectric power, however, provides 7 percent of our electricity, and nuclear power nearly 20 percent. These sources have other drawbacks, but throw off little or no CO 2.
If your electricity comes from a dirtier source (you can find out here), then the energy used in your household may amount to more than twice the greenhouse-gas emissions of an average car. Which leaves trimming CO2 pounds from electricity partially up to you. Distressingly, 40 percent of all household electricity used to power electronics is consumed while they are turned off. Below are tips for cutting back on your electricity use. We promise you won't have to live in the dark, and, conveniently, you should save on your electric bill as well:
• If every American household replaced just one incandescent light bulb with a CFL, we'd prevent 800,000 cars' worth of greenhouse-gas emissions.
• Replace your halogen bulbs, too. They can get as hot as 1,100 degrees Fahrenheit, which means you could cook an egg on one. CFLs will save you money, as well as CO2 pounds.
• Cable and video-game boxes, DVD players, and other electronics can use as much energy in standby mode as a 75-watt light bulb that's left on. If a device offers an "off" option for standby lights, use it. Otherwise, try plugging electronics into a power strip, which you can turn off when they're not in use.
• How many times have you left your cell-phone charger plugged in, even when your phone is not? Wall chargers for things like iPods and cameras suck energy out of the socket, even when not attached to their mates. With the national average at five chargers per person, unplugging adds up.
• Rechargeable battery docks for gadgets like drills and handheld vacuum cleaners can draw from the socket five to 20 times more energy than is stored in the battery. Unplug them once tools are juiced.
• When replacing an appliance, look for the Environmental Protection Agency's Energy Star label, which indicates higher efficiency than what's legally required.