The formation of effective policies to reduce emissions from goods movement should consider local and remote life-cycle effects as well as barriers for mode shifting. Using uni- and multi-modal freight movements by truck, rail, and ocean-going vessel associated with California, a life-cycle assessment (LCA) is developed to estimate the local and remote emissions that occur from freight activity inside and associated with the state. Long-run average per tonne-km results show that ocean going vessels emit the fewest emissions, followed by rail, then trucks, and that the inclusion of life-cycle processes can increase impacts by up to 32% for energy and GHG emissions and 4,200% for conventional air pollutants. Efforts to reduce emissions through mode shifting should recognize that infrastructure and market configurations may be inimical to mode substitution. A uni- and multi-modal shipping emissions assessment is developed for intrastate and California-associated freight movements to illustrate the life-cycle impacts of typical trips for certain types of goods. When targeting greenhouse gas reductions in California it should be recognized that heavy-duty trucks are responsible for 99% of intrastate goods movement emissions. An assessment of future freight truck technology improvements is performed to estimate the effectiveness of strategies to meet 2050 greenhouse gas reduction goals. While aggressive improvements in fuel economy coupled with alternative vehicles and fuels can significantly reduce GHG emissions, to meet 2050 goals will likely require zero carbon emission vehicle technology. The value of using LCA in GHG reduction policy for transportation systems is explored.
Environ. Sci. Technol., 2007, 41 (20), pp 7138–7144 DOI: 10.1021/es070989q
Life-cycle air emission factors associated with road, rail, and air transportation of freight in the United States are analyzed. All life-cycle phases of vehicles, infrastructure, and fuels are accounted for in a hybrid life-cycle assessment (LCA). It includes not only fuel combustion, but also emissions from vehicle manufacturing, maintenance, and end of life, infrastructure construction, operation, maintenance, and end of life, and petroleum exploration, refining, and fuel distribution. Results indicate that total life-cycle emissions of freight transportation modes are underestimated if only tailpipe emissions are accounted for. In the case of CO2 and NOx, tailpipe emissions underestimate total emissions by up to 38%, depending on the mode. Total life-cycle emissions of CO and SO2 are up to seven times higher than tailpipe emissions. Sensitivity analysis considers the effects of vehicle type, geography, and mode efficiency on the final results. Policy implications of this analysis are also discussed. For example, while it is widely assumed that currently proposed regulations will result in substantial reductions in emissions, we find that this is true for NOx emissions, because fuel combustion is the main cause, and to a lesser extent for SO2, but not for PM10 emissions, which are significantly affected by the other life-cycle phases.
This study provides a life cycle inventory of air emissions (CO2, NOx, PM10, and CO) associated with the transportation of goods by road, rail, and air in the U.S. It includes the manufacturing, use, maintenance, and end-of-life of vehicles, the construction, operation, maintenance, and end-of-life of transportation infrastructure, as well as oil exploration, fuel refining, and fuel distribution.
Environmental awareness is increasingly important to society, government, and industry, and there is a strong demand for sustainable development practices. The importance of supply chain management is critical, as it characterizes and influences the life cycles of all products. Within the major logistics trends, outsourcing has a significant potential to increase sustainability in the supply chain as third-party logistics providers (3PLs) focus on improving resource utilization and making processes more efficient. However, their motivation is largely economic, and an environmental perspective is rarely seen in 3PLs. As consumers demand greener alternatives and, subsequently, environmental regulatory measures are implemented, 3PLs will have to become more environmentally and socially aware in order to develop sustainability goals. This study compares two scenarios using life-cycle assessment (LCA): one where logistics functions are handled in-house, and an alternative scenario where such functions are outsourced to a 3PL. The impacts of logistics outsourcing on energy utilization, global warming potential, and fatalities are first quantified in the supply chain of an automobile. Even though vehicle operation, responsible for most of the impacts considered, is outside the domain of logistics functions, logistics outsourcing nonetheless has the potential to reduce energy use and global warming potential by 0.4–2% and fatalities by 0.8–3.3% throughout the entire life cycle of a typical automobile. Road and air transportation are found to account for most of the impacts in all selected metrics. Analyzing logistics outsourcing in the other sectors of the U.S. economy revealed the same trend as observed in the supply chain of an automobile.