Sustainability impacts of a program of decommissioning older automobiles for replacement with newer, more efficient vehicles

This paper investigates a representative vehicle replacement scenario on a comprehensive basis, including energy for fabrication, operation and decommissioning, together with the associated environmental and economic impacts. It is postulated that to lessen the environmental impact of older, inefficient devices, legislation may be passed to require the decommissioning and purchase of newer equipment. However, the energy consumed, greenhouse gases emitted, and economic costs of building a new product and decommissioning the old product may outweigh the benefit of removing an inefficient device from service on a life-cycle basis. A representative case of retirement of automobiles from 1990 and earlier by comparable 2007 model internal combustion engine automobiles is considered. The energy use, greenhouse gas emissions, and economic cost to the consumer are compared for two cases, one that includes the production and operation of a new car and decommissioning of the older car, and a second case accounting for only the continued operation of the older car. It was found that from an energy and emissions standpoint, it is beneficial to require the decommissioning of older automobiles. However in the same time period, economic considerations from the customer's perspective favor continued operation of the older automobile. Therefore, the study concludes that without such an economic basis, legislation and incentives would be required to enable the replacement of older automobiles with more efficient models.