A strategy for reducing emissions of greenhouse gases from personal travel in Britain

The presence of ‘greenhouse gases’ in the atmosphere has a warming effect on the biosphere, making the world habitable for life. Human activities, particularly energy use and deforestation, are increasing the concentration of these gases, and in particular carbon dioxide (CO;?). Many climatologists believe that the global temperature is beginning to rise as a result. The intergovernmental Panel on Climate Change (IPCC) has recommended that emissions of CO2 be cut by 60 per cent in order to stabilise the atmospheric concenaation of this gas and to minimise the resulting disruption to the world’s climate. Transport is currently Britain’s fastest growing source of carbon dioxide, the principal anthropogenic greenhouse gas. An assessment is made of the relative contributions to CO2 emissions of different forms of travel, and trends in energy use are surveyed. Emissions of CO2 from ‘secondary’ sources, such as vehicle production, are also examined. A computer model called SPACE is described, which was developed in order to assess CO2 emissions under different policy scenarios up to the year 2025. A ‘business as usual’ scenario predicts that emissions will rise substantially, mainly as a result of an ongoing rise in road traffic. This contrasts with the Government’s stated aim of stabilising emissions of CO2 at the 1990 level by 2000. A modification of this scenario, in which technological improvements to vehicles are vigorously applied, shows a reduced growth in emissions. A third scenario then examines the effect of a combination of technological and demand management policies, and demonstrates a significant reduction in emissions. Scenario 3 adopts what are seen as fairly modest policy measures, making use of their synergistic effect. The main justification for this ‘non-radical’ approach is public and political acceptability. It is, however, recognised that most of the policy measures could be applied more vigorously if required if it is assumed that transport is allotted a less stringent target than other energy-consuming sectors, the reduction in emissions projected in Scenario 3 is consistent with the IPCC goal of atmospheric CO;? stabilisation. Data sets compiled as part of the SPACE model can be made available on request.