Life Cycle Emissions
Life cycle assessment tracks emissions generated and materials consumed for a product system over its entire life cycle, from cradle to grave, including material production, product manufacture, product use, product maintenance and disposal at end of life. For vehicles, this includes the environmental burdens for making materials (e.g., steel, aluminum, brass, copper, various plastics, etc.), fabricating them into parts, assembling the parts into a vehicle, operating the vehicle over its entire lifetime, producing fuel for the vehicle, maintaining the vehicle and finally disposing of the vehicle at the end of its life. Life cycle assessment is an essential tool in thinking about the environmental impacts of complex systems.
The table below details the results of a life cycle analysis for a representative mid-size car and SUV in the United States. Life cycle CO2 emissions from vehicles are dominated by CO2 released during fuel consumption. Product disposal has a minor impact on airborne emissions and energy consumption relative to other phases of the product system (approximately 2 percent).
Because many assumptions were required to generate such a figure, many of which we have little or no control over, we do not expect to use the estimate as an ongoing performance measure. It did, however, enable us to better understand the total system dynamics and the opportunities for reducing emissions.
