Travel & transport: how far can we go on renewables?
Sometimes there is a slight smell of chips frying around my car, when it is running on recycled vegetable oil. Using plant-based waste products must be among the best ways to cut carbon dioxide (CO 2 ) emissions from driving a car. However, even if we persuade people to eat more chips, the supply of recycled cooking oil will be quite limited. So how much can renewables and technology contribute to greenhouse gas emission reductions? In the UK, burning transport fuels (for passenger and freight transport by land, sea and air) produces about sixty million tonnes of CO 2 (about one quarter of all UK emissions). Roughly half of this comes from cars, one quarter from road freight and one quarter from aviation. Nitrogen oxides and water vapour emitted by aircraft at high level add considerably to the global warming impact of their CO 2 emissions, roughly tripling the effect. Biofuels – fuels from plants – are the main near-term option for renewable transport energy. In principle, CO 2 produced when the fuels are burned is offset by the CO 2 absorbed by growing plants. However, at present biofuels produced mainly from input-intensive food crops, and greenhouse gas emissions in production can halve the benefits. Meanwhile, growing biofuels
reduces the land available for food production and preserving biodiversity and importing biofuels can damage the environment in the countries where they are grown. In the near term, the European Union and the UK government aim for biofuels to provide about five per cent of transport energy by blending them with conventional fuel. Diesel fuel containing five per cent bio-diesel is already on sale in some outlets. In the longer term, biofuels from wood or agricultural waste are likely to be developed. They have a much better CO 2 balance than fuels from food crops, provide more energy for a given land area, and can be produced from lowergrade land. If transport demand stopped growing, the government target of sixty per cent reduction in greenhouse gas emissions by 2050 might be achievable through improved efficiency and using renewable energy. However, much deeper reductions are needed to reduce the risk of catastrophic climate change. Renewable energy is unlikely to offer more than a partial solution, so we need to minimise car use, air travel and freight transport. Some advices and queries for Friends might include: • Could you organise your life so more journeys could be made on foot, by bicycle, or by public transport? When choosing
where to live, do you place a high priority on accessibility by sustainable means of transport? If your work involves travel, could you or your employer try tele-conferencing instead? Could you work from home one or two days a week? • When choosing a car, look at the CO2 emission figures and choose one that meets your needs with minimum emissions. Does your driving style minimise fuel consumption? Keep engine revs down and minimise the use of brakes. Adopt a lower cruising speed when possible. Keep your vehicle well maintained and ensure tyres are up to pressure. • Avoid flying when it is not essential. Can your objective be met closer to home, or can your journey be made by other means? • Reduce the demands your purchases of food and other goods place on the environment, seeking local and seasonal foods, and try to avoid produce brought in by air freight. So – renewables and energy efficiency can probably go some way to reconciling our desire for travel with the needs of the planet, but we had better start taking George Fox’s advice more literally and get on with walking cheerfully over the world!
the Friend , 5 January 2007 7