Extract

Carbon dioxide equivalent greenhouse gas emissions arise when fuel with embodied carbon is used by vehicles to satisfy their propulsion requirements. The emission of other air pollutants arises from the use of such fuel. Mass is the largest determinant of the energy and power required by a vehicle to complete a journey (Goldberg, 2000). Additional energy is required to overcome both the drag (forces), which acts on the vehicle in motion, and the losses from the conversion of potential energy to kinetic energy, such as in an engine. The total demand for transport accounted for 27 per cent of global energy use in 2008. Road transport was responsible for 74 per cent of that total, followed by marine, aviation and rail at 16 per cent, 11 per cent and 2 per cent, respectively (IEA, 2010, see also Chapter 8). There are two components that determine the extent to which energy use and emissions of greenhouse gases and other pollutants, more importantly, may be reduced or eliminated from transport. First, novel technologies can yield an immediate, but one-off, efficiency boost when incorporated either with new vehicles or as retrofits to those already in service. Second, energy use and associated emissions can be reduced on an ongoing basis through more efficient vehicle operation.