High-speed rail's potential for the reduction of carbon dioxide emissions from short haul aviation: a longitudinal study of modal substitution from an energy generation and renewable energy perspective

This paper quantifies and evaluates, utilising a 'bottom-up' approach, the effect on CO 2 emissions of a modal shift from short-haul air travel to high-speed rail (HSR), based on projected passenger movements, between Sydney and Melbourne, Australia during the period 2010--2030. To date, peer-reviewed studies assessing the CO 2 emissions from these competing modes of high-speed transportation have been restricted principally to a cross-sectional assessment, with a Eurocentric bias. This present comparative study seeks to address a gap in the literature by assessing, longitudinally, the CO 2 emissions associated with the proposed operation of HSR against the 'business-as-usual' air scenario between Sydney and Melbourne. Under the assumed 50/50 modal shift, and the Australian government's current renewable electricity target, an annual reduction in CO 2 emissions of approximately 14% could be achieved when compared with a 'business-as-usual' air scenario. This percentage reduction represents a 62 kt reduction in base year, 2010, and a 114 kt reduction in the final year, 2030. In total, the overall reduction achieved by such a modal shift, under the assumed conditions, during the period 2010--2030, equates to approximately 1.87 Mt of CO 2 . Importantly, if the electrical energy supply for HSR operations was further 'decarbonised', then it follows that a greater emission reduction would be achieved.