Greenhouse Gas Equivalencies Calculator (United States Environmental Protection Agency)

Did you ever wonder what reducing carbon dioxide (CO2) emissions by one million metric tons means in everyday terms? The EPA online equivalency calculator can help you understand just that.

The Environmental Protection Agency online calculator lets individuals, government agencies and companies translate greenhouse gas reduction estimates into everyday terms. The Greenhouse Gas Equivalences Calculator converts carbon dioxide (CO2) emissions, typically presented in million metric tons of carbon dioxide equivalents, into terms such as number of cars per year, barrels of oil or gasoline, or energy for a number of homes per year. The calculator also converts emission metrics into tanker trucks' worth of gasoline, trees per acre, waste recycling or electricity generated from coal-fired power plants for a year. Users can enter savings in emissions, electricity consumption, gallons of gasoline or number of vehicles into the greenhouse gas calculator and generate up to 13 different ways to express the magnitude of the savings. The calculator uses the agency's Emissions and Generation Resource Integrated Database (eGRID). That database converts kilowatt-hours of electricity generation into units of carbon dioxide emissions. The eGRID contains a comprehensive environmental performance record of electric power systems nationwide. It uses plant-specific data for all U.S. electricity generating plants that provide power to the electric grid. The agency's eGRID system contains air emissions data for nitrogen oxides, sulfur dioxide, carbon dioxide and mercury. The latest version, eGRID2006 Version 2.1, includes data up to 2004, the latest available, EPA said in a statement announcing the online calculator's launch. Utilities and other companies that own electricity generating plants report data on fuel consumption, generation, and emissions, along with plant identification, location, and structural information to the EPA. The eGRID data covers almost all the electricity generating units nationwide. The system also allows users to sort the emissions, generation and rate data by state, electric generating company, parent company, power control area, eGRID subregion, power pool and U.S. total levels. The EPA developed the calculator to help individuals and organizations reduce their greenhouse gas emissions, develop reduction targets and accurately publicize pollution reduction strategies. EPA’s online tool shows that if a typical household switched all its incandescent light bulbs to Energy Star qualified compact fluorescent bulbs, it would save about 75 percent of its lighting electricity use, or about 1,463 kWh a year. After five years, these savings are equivalent to conserving 530 gallons of gasoline or recycling 1.6 tons of waste.