Green transport is a category of sustainable transport which uses human power, animal power and renewable energy. In common usage public transport is considered a green transport option in comparison with private vehicles, as is car pooling. But some people prefer a definition that does not include public transport or vehicle movements which relies on non-renewable energy.
Green transport includes:
- cycling and some other types of human-powered transport
- Green vehicles
- solar powered vehicles
- wind powered vehicles
Often there can be a sliding scale of green transport depending on the sustainability of the option. Public transport on traditional diesel buses uses less fuel per passenger than private vehicles so is more green than private vehicles, but is not as green as using a solar powered bus. It can often be useful to talk about moving a community towards the ultimate green mode transport outcomes - instead of declaring that they are there if they cross a particular sustainability threshold. Walking across sensitive environments can often cause considerable damage and so is not always the greenest option.
Green transportation is for reducing the environmental damage originated in individual's use of cars and light trucks.
Alternative Fuel Vehicle refers to a vehicle that runs on a fuel other than "traditional" petroleum fuels (petrol or diesel); any method of powering an engine that does not involve solely petroleum (e.g. electric car, petrol-electric hybrid, solar powered). Due to a combination of heavy taxes on fuel, particularly in Europe; tightening environmental laws, particularly in California; the potential for peak oil, and the possibility of further restrictions on greenhouse gas emissions, work on alternative power systems for vehicles has become a high priority for governments and vehicle manufacturers around the world.
"Hybrid" vehicles such as the Toyota Prius are not, of themselves, alternative fuel vehicles - clever use of a battery, motor/generator, merely means that a more efficient but less powerful engine can be used. Essentially all the power comes from petroleum. The first hybrid vehicle available for sale in the United States was the Honda Insight, achieving around 70 miles per gallon (3.4 liters per 100 km). Other research and development efforts in alternative forms of power focus on developing fuel cells, alternative forms of combustion such as GDI and HCCI, and even the stored energy of compressed air (see Air Engine).
Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License)