Pathways to Reduced Transportation CO2

This report explores pathways to reducing transportation based carbon dioxide emissions in the United States. The goal is to analyze the feasibility of reducing the level of transportation based carbon dioxide emissions in 2050 to 50% of the level they were at in 2005. Emissions have been steadily rising over the past century, and if left uncurbed, will have a negative effect on the quality of life of future generations. The primary purpose of this report is to analyze different alternate technologies that can be implemented in passenger vehicles, freight vehicles, and freight rail transportation, as those sectors are the largest contributors to transportation emissions. While air transport is also a significant contributor, it will not be considered in this analysis. The alternative technologies analyzed are diesel engines, natural gas, ethanol, hydrogen fuel cells, biodiesel, hybrid passenger vehicles, hydraulic hybrid trucks, plug in electric passenger vehicles, plug in hybrid passenger vehicles, best-practice diesel truck, truck to rail mode shifting, hybrid rail engines, and electric rail systems. After exploring the mechanisms that drive these alternate technologies, and the impact they can have on reducing carbon dioxide emissions, a model was constructed that effectively forecasted the passenger and freight transportation volumes, and the resulting carbon dioxide emissions from each year, depending on which technologies are implemented. The model can be manipulated by the user, allowing any combination of alternative technologies to be employed. Next, the technologies that seemed to have the most effective impact on reducing emissions were analyzed as to their feasibility of large-scale implementation. Passenger vehicle based emissions had the greatest reduction when biodiesel was fully implemented as the primary fuel. Also, electric cars were found to have a high carbon dioxide reduction potential, but the efficiency improvement is contingent on the United States moving to a more sustainable energy profile. Ethanol also has the potential to help reduce the carbon dioxide emissions of the United States, but an analysis showed that ethanol made from sources other than corn with a lower lifecycle CO 2 content and production efficiency would be required. Electric cars, hybrids, and plug-in hybrids can also greatly reduce carbon dioxide emissions when used in tandem with biofuels or a more sustainable energy profile. The most effective increase in efficiency was found to be when freight tonnage was mode-shifted to rail transport. However, mode shifting in freight is limited by the commodities that can be effectively transported …