Waste
We based our estimate of the environmental impact of household waste on data from the EPA, with 1010lbs. per person annually being the average. This average was obtained by dividing the tons of waste deposited annually at US landfills by US population.
Emissions = number of people in household * average lb CO2 equivalent. generated from waste per person per year [Source: Based on EPA's Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2004, Chapter 8, Table 8-3]
How Was the Reduction Calculated?
Home
Replacing incandescent light bulbs with compact fluorescents: assumes that lights are on for 4 hours per day.
Replacing old refrigerator with an ENERGY STARĀ® model: assumes old model uses 820 kWh per year; ENERGY STAR model uses 440 kWh per year.
Turning up thermostat for central air conditioner: assumes average household electricity use of approximately 900 kWh per month, and that air conditioners account for 16 percent of residential electricity consumption. [Source: EIA 2001. End-use Consumption of Electricity]
Turning down thermostat in winter: assumes 1 percent savings in energy use for a 1 degree decrease. assumes thermostat is turned down for 8 hours each night November through March.
Replacing single-glazed windows with ENERGY STAR windows: Assumes 2000 square-foot house, 300 square feet of glass, gas heat, and electric air conditioning.
Replacing an old boiler or furnace with an ENERGY STAR model: Assumes a 20 percent savings on heating fuel costs.
Except where noted above, all home emissions reductions were based on data from: ENERGY STAR.
Transportation
Emissions reductions were calculated using the same formulas shown above, and the resulting amount was subtracted from your previous total
Waste
For our estimated reduction in greenhouse gas emissions that you can achieve by recycling, we used emissions data for each source: newspaper, glass, plastic, and metal. Our reduction calculations assume that households recycle 100 percent of all recyclable materials generated as waste. The plastic material type used in the calculator includes PET and HDPE, and the metal material type includes aluminum and steel cans.
[Emissions Factors Source: U.S. Environmental Protection Agency, 2006. Solid Waste Management and Greenhouse Gases: A Life-Cycle Assessment of Emissions and Sinks, EPA530-R-06-004.]
FInd energy data from the US Energy Information Administration online at: http://www.eia.doe.gov/
Environmental information can be found online at: http://www.epa.gov/
Find energy data for home and transportation fuel use online at: http://www.eia.doe.gov/oiaf/1605/coefficients.html
Want to know more about carbon footprints? Visit the Wikipedia page: http://en.wikipedia.org/wiki/Carbon_footprint