Household Emissions Calculator Assumptions and References

Your Current Household Emissions Sources

Transportation

Pounds of carbon dioxide equivalent are calculated based on EPA's estimate of the greenhouse gas emissions from a typical passenger vehicle in the United States. Estimates of the typical values for fuel economy and miles driven per week are from the same source. Note that EPA's emissions estimates are lower than estimates obtained through fueleconomy.gov, because EPA's estimates are for tailpipe emissions only. The fueleconomy.gov site estimates emissions over the full fuel lifecycle (including extraction, processing, and transportation of fuel).

Electricity

Electricity emissions factors are categorized by geographic subregion. Source: EPA. eGRID Version 2.1 Plant File, 2006.

"Typical" annual CO₂ emissions are 16,290 pounds per household, assuming approximately 900 kWh per month. Source: EPA. Unit Conversions, Emissions Factors, and Other Reference Data (PDF, 16 pp., 152 kb, About PDF).

Natural Gas

Carbon coefficient for natural gas: 117 pounds of CO₂ per million BTU, or 0.12 pounds per cubic foot of gas. Source: U.S. EPA Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2004, Annex 2, Table A-30.

"Typical" annual CO₂ emissions of 11,000 pounds per household based on national average monthly consumption of 7,680 cubic feet of gas. Source: U.S. Energy Information Administration 2004. A Look at Residential Energy Consumption in 2001.

Fuel Oil

Carbon coefficient for distillate fuel (fuel oil): 161.44 pounds of CO₂ per million BTU, or 22.29 pounds per gallon. Source: U.S. EPA Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2004, Annex 2, Table A-30.

"Typical" annual CO₂ emissions of 14,500 pounds per household based on national average monthly consumption of 55 gallons of oil. Source: U.S. Energy Information Administration 2004. A Look at Residential Energy Consumption in 2001.

Waste Disposal

Estimates of greenhouse gas emission benefits from recycling newspaper, glass, plastic, metal, and magazines were developed using national waste data and life-cycle greenhouse gas emission factors for waste management. Calculations assume that it would be possible for households to recycle 100 percent of all recyclablematerials generated as waste. For example, if you indicate that you recycle newspapers, this calculator assumes that you recycle 100 percent of the newspapers you receive. It is estimated that on average, each person generates 0.041 metric tons of newspaper, 0.043 tons of glass, 0.014 metric tons of plastic, 0.012 metric tons of metal, and 0.009 metric tons of magazines per year.

EPA's annual Characterization Report was the source of per capita waste generation by material type (e.g., newspaper waste generated per person). Source: U.S. Environmental Protection Agency, 2005. Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2003.

Carbon dioxide equivalent emissions associated with household waste management were calculated using the total emissions for landfills (including incineration, landfill gas-to- energy projects, oxidation, and flaring) from EPA's Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2004 and the United States population estimates from EPA's annual Characterization Report mentioned above. The emission factors for each material type were developed by EPA and presented in the Agency's report on greenhouse gas emissions from waste management and in the online WAste Reduction Model (WARM). These emission factors take into account the full material life cycle; i.e., not only emissions at the landfill, but also emissions and sequestration associated with production, manufacturing, remanufacturing, forest carbon storage due to reduced harvests, etc. The emission factor used for recycling materials in this calculator compares greenhouse gas emissions from recycling with those attributable to landfilling. This approach enables policy makers to evaluate, on a per-ton basis, the overall difference in greenhouse gas emissions between (1) recycling 1 ton of material and (2) manufacturing and then managing (post-consumer) 1 ton of the same material. 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. WARM is available in the Tools section of the Waste section of this Web site.

What You Can Do to Reduce Your Emissions

On the Road

Emission factors based on EPA's estimate of the greenhouse gas emissions from a typical passenger vehicle in the United States.

Cost savings for reducing the number of miles driven are calculated using $0.16 cents per mile (includes gas, oil and maintenance). Source: Transportation Energy Data Book. Table 10.11. Average variable cost per mile, 2006.

Properly inflating tires: Assumes an increase in fuel efficiency of 3 percent. Keeping your engine properly tuned: Assumes an increase in fuel efficiency of 4 percent. Source: Environmental Protection Agency and Department of Energy, Fuel Economy Website, 2007.

Perform regular maintenance on your vehicles: Assumes an increase in fuel efficiency of 7 percent. Source: Environmental Protection Agency and Department of Energy, Fuel Economy Website, 2007.

Cost savings for purchasing a more fuel efficient vehicle are calculated using $3.01 per gallon. Source: EIA US Retail Gasoline Prices, June, 2007.

At Home

Cost savings for natural gas consuming devices assume an average cost of $13.76 per thousand cubic feet. Source: Energy Information Administration: Natural Gas Annual, 2006.

Cost savings for electricity consuming devices assume average cost per kWh of $0.1. Source: Energy Information Administration, Form EIA-826, "Monthly Flash Estimates of Electric Power Data," 2006.

Cost savings for fuel oil consuming devices assume an average cost of $2.37 per gallon. Source: Energy Information Administration: US No. 2 Distillate Prices by Sales Type, Table 15, 2006.

Turning down your heating thermostat: 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. Source: U.S. Department of Energy. A Consumer's Guide to Energy Efficiency and Renewable Energy, 2005.

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: U.S. Energy Information Administration. End-use Consumption of Electricity.

Enable sleep feature on your computer and monitor. Assumes ENERGY STAR desktop computer and monitor. Average annual unit computer energy (sleep feature enabled, left on): 96 kWh; Average annual unit computer energy (sleep feature not enabled, left on): 506 kWh; Average annual unit monitor energy (sleep feature enabled, left on): 32 kWh; Average annual unit monitor energy (sleep feature not enabled, left on): 175 kWh. Source: ENERGY STAR. Cost Estimate for Energy Star Qualified Computers and Monitors, 2006.

Wash clothes in cold water instead of hot: Assumes average use of 420 kWh per year or 1.07 kWh per load. Source: D&R International product database, 2007.

Use a clothes line or drying rack for 50% of your laundry, instead of your dryer: Assumes 750 kWh of electricity used per year. Source: U.S. Department of Energy. A Consumer's Guide to Energy Efficiency and Renewable Energy, 2005.

Replacing 75 watt incandescent light bulbs with 25 watt compact fluorescents: Assumes that lights are on for 4 hours per day. Source: ENERGY STAR. Cost Estimate for Energy Star Qualified Light Bulbs, 2006.

Replacing old refrigerator with an ENERGY STAR model: Assumes old model uses 820 kWh per year; ENERGY STAR model uses 440 kWh per year. Source: ENERGY STAR. Cost Estimate for Energy Star Qualified Refrigerator, 2006.

Replacing an old boiler or furnace with an ENERGY STAR model: Assumes 2000 sq ft house; 300 square feet of glass. Source: ENERGY STAR. Cost Estimate for Energy Star Qualified Furnaces, 2006.

Replacing single-pane windows with ENERGY STAR windows: Assumes 2000 square-foot house, 300 square feet of glass. Source: ENERGY STAR. Methodology based on RESFEN 3.1 calculations performed by Lawrence Berkeley National Laboratory (LBNL), 2005.

Recycling

Calculations assume that it would be possible for households to 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.

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