Life cycle comparison of passenger air and rail transportation

Air transportation has an undisputed speed advantage among all other modes. On the other hand, it is known that the environmental metrics of aviation is quite unsatisfactory compared to other transportation types due to its fuel characteristics and the amount of consumed fuel. However, it would be a wrong choice to rely solely on operational processes to make a true comparison. For this reason, a Life Cycle Assessment (LCA) model should be generated by taking into account processes such as production except the operation process and the calculations should be performed with a comprehensive and holistic perspective. In this study, the environmental impacts of air and rail transport types are compared from the life cycle perspective. For this purpose, first, the emissions in the case of one passenger per one km (pkm) transportation by air and rail were calculated. Then, taking into account the production and disposal processes of the aircraft and passenger trains, the LCA cycle was completed and total emissions were calculated. SimaPro version 9.0.0.49 package program and 1.09 version of ReCiPe 2008 method were used for LCA calculations. With the help of the program, emissions generated during both production and one pkm transportation processes of an aircraft, high-speed and normal train were estimated. Accordingly, the greenhouse gas produced one pkm in air transport was 126.8 g in terms of carbon dioxide equivalent (CO_2eq), while CO_2eq was 0.3 and 0.31 g for high-speed trains and regular trains, respectively. Considering the production processes, 2072.1, 28.72, and 19.07 t of greenhouse gases are produced, respectively for these three transportation modes.