Quantifying Our Environmental Impacts

The first important step in improving the life-cycle impacts of our products is to understand the environmental aspects of our products and the potential environmental impacts associated with them.1 The stages of a vehicle's life-cycle include materials production, parts fabrication, vehicle assembly, vehicle operation (including fuel production), maintenance and repair, and end-of-life disposal and recycling. While estimates vary depending upon the specifics of the vehicle analyzed, one cooperative, multi-industry analysis of a typical family sedan (a spark-ignited, gasoline-powered, Taurus-class family sedan weighing 1,532 kilograms (kg)) found that during its life-cycle:

• 960 gigajoules of energy are consumed
• 21,000 kg of hydrocarbon are consumed
• 60,000 kg of carbon dioxide are emitted

In that study, it was assumed that the vehicle was driven a total of 120,000 miles at an average metro/highway fuel efficiency of 22.8 mpg. The study also found that:

• Vehicle operation consumes 86 percent of the life-cycle energy
• Vehicle operation generates 87 percent of the life-cycle CO2
• Vehicle production generates 65 percent of the particulates and 34 percent of the life-cycle sulfur dioxide

This is consistent with a recent review of life-cycle studies, in which it was found that the operational stage generally accounts for 80 to 90 percent of the total energy consumption and CO2 emissions of conventional gasoline-powered vehicles, depending on the vehicle's material composition, average fuel efficiency and lifetime drive distance. For example, a 2006 life-cycle assessment study of the Ford Galaxy and S-MAX, confirmed that the vehicle's use-phase consumes more energy and produces more CO2 emissions than the vehicle's other life-cycle phases. Other impact categories are mainly dominated by the mining and materials production phases.