The Science Behind Making the Switch
Posted: 02-Jun-2006; Updated: 29-Aug-2007
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How are we counting carbon?
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The average 25-watt compact fluorescent light (CFL) bulb generates as much light as a 75-watt incandescent light bulb, but uses less than a third the energy. Through the energy savings, a 25-watt CFL bulb reduces the amount of carbon dioxide emissions by more than 1,000 pounds over the lifetime of the bulb, assuming a 15,000-hour life for the CFL.
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Our carbon count is an estimate of how much carbon pollution we're all pledging to save. While some of are changing 60- or 100-watt bulbs, we are calculating this number based on a 75-watt bulb, using it as an average.
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Check out the chart below for a more detailed estimate of how much carbon pollution you can prevent based on the bulbs you switch out. Also check out your cost savings per bulb! Who said you have to choose between the environment and the economy?
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Incandescent..CFL........Lumens..Cost Savings..CO2 Savings
40W.................11-14W...490........$39-$44.........507-572 lbs.
60W.................15-19W...900........$62-$68.........806-884 lbs.
75W..................20-25W..1,200.....$76-$839.......88-1,079 lbs.
100W...............26-29W...1,750.....$107-$112...1,391-1,456 lbs.
150W...............38-42W...2,600.....$163-$169...2,119-2,197 lbs.
. Calculations for cost and CO2 savings assume 15,000-hour
life for CFL.
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What does this compare to?
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The average American is responsible for 8.4 metric tons of carbon dioxide emissions per year, according to an analysis by the Rocky Mountain Institute. This includes emissions from residential sector energy use, household vehicles and equipment, and commercial aviation.
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What about cars? Burning one gallon of gasoline releases 19 pounds of CO2. But if every household replaced just three 60-watt incandescent light bulbs with CFLs, we would reduce as much pollution as if we took 3.5 million cars off the roads!
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How else can you cut your global warming pollution?
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Did you know - if your new car gets 3 mpg more than your old one, you can reduce CO2 emissions by 3,000 pounds per year? Small changes in your household or on the road can make a big difference. Visit our Fight Global Warming consumer site for more tips on what you can do.
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We’ll help you put yourself on a Low Carbon Diet. Check out our printable Low Carbon Diet Guide [PDF] for more useful tips.
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Article Link
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Environmental Defense
http://www.environmentaldefense.org/home.cfm