Decarbonising the Road Transport Sector-policy Options in the Medium- and Long-run
J Liu, G Santos, University of Oxford, UK
The paper applies two models from the US Department of Energy: the GREET model and the VISION model to quantitatively evaluate and compare the various impacts of four promising vehicle/fuel technologies with a break-even analysis for each of them.
Transport currently accounts for 14% of global CO2 emissions, to which road transport alone contributes 45%. In most OECD countries, transport is responsible for more than 25% of all GHG emissions and the relative share is estimated to further increase in the future. Under the scenario of business as usual, road transport emissions will be doubled by 2050 and will become one of the main causes of global warming. The global temperature will correspondingly raise by 2-3 degrees centigrade by 2050., which in turn will result in various negative environmental effects, such as extreme weather, sea level rise, floods, droughts, population displacement, ecosystem destruction, malnutrition and so on.Meeting in Japan in July 2008, the leaders of the Group of Eight (G8) nations (Canada, France, Germany, Italy, Japan, Russia, the United Kingdom and the United States) agreed to cut carbon emissions by at least 50 per cent by 2050, and if this is to be understood with respect to 1990 levels, then the G8 are facing a major challenge, which is to decarbonise the economy. Transport is an extremely difficult sector to decarbonise and hence, the subject of this study.
The paper applies two well-known and widely tested models from the US Department of Energy: the GREET model (Greenhouse gases Regulated Emissions and Energy Use in Transportation) and the VISION model to quantitatively evaluate and compare the various impacts of four promising vehicle/fuel technologies: biomass-based fuels for internal combustion engine vehicles and renewable energy to produce hydrogen for fuel cell vehicles and/or electricity for plug-in hybrids and pure battery electric vehicles. For each of the four vehicle/fuel technologies consumption of total energy, emissions of CO2 and emissions of six pollutants are estimated for the USA for the year 2020 (as a representative of medium-term) and for the year 2050 (as a representative of long-term). The six pollutants are volatile organic compounds (VOCs), carbon monoxide (CO), nitrogen oxide (NOx), particulate matter with a size smaller than 10 microns (PM10), particulate matter with a size smaller than 2.5 microns (PM2.5), and sulfur oxides (SOx). Although the estimates rest on a number of assumptions for the parameters entered in the model they give an idea of the possible impacts of the adoption of these technologies. A sensitivity analysis is also conducted to establish the robustness of the results.
Finally a break-even analysis (free of taxes and subsidies) is presented for each of the four vehicle/fuel technologies under consideration in order to compare them. These estimates also necessarily rest on assumptions about future prices and costs, and therefore a sensitivity analysis is also carried out.
The paper concludes with some final considerations on vehicle and fuel taxes and subsidies which, as expected, alter the results of the break-even analysis. This exercise is conducted to get an idea of the type and magnitude of incentives that may be needed to decarbonise the road transport sector.
Although a substantial amount of research has and is being conducted in this area, no study has put all these elements together in one comprehensive analysis yet. The contribution of this paper is to present, by way of a break-even graph, a clear comparison of four of the vehicle/fuel technologies which are either are in the market already or are being developed to be in the market in two or three decades and beyond.
Association for European Transport