The most important groups of fuels are fossil fuels, bio-fuels, hydrogen and nuclear fuel (uranium). Of these fuels, only bio-fuels and hydrogen are strictly renewable, but in both cases, this really depends on the energy source used to produce it. We have traditionally been heavily dependent on fossil fuels (first coal, then oil and now natural gas) and more recently on nuclear power. In the future, we will need a more sustainable range of fuels for all potential uses. New technologies such as fuel cells may require a wider range of fuels (e.g. hydrogen) and widen the range of applications for which fuels may be used (e.g. methanol-fuelled fuel cells to power laptops). There are many controversial topics surrounding fuels, from carbon emissions and climate change through the potential for bio-fuel crops to compete with food crops to the whole debate around nuclear power generation. - Description added by: David Lockie

Transport is responsible for a large proportion of carbon emissions. As high carbon fossil fuels are largely used to power all types of transport - from road to rail, marine to aviation - carbon dioxide and other greenhouse gases are released into the atmosphere, contributing to climate change. Using public transport and technologies to improve energy efficiency, hybrid vehicles, electric vehicles, bio fuels and fuel cell vehicles are all vital components in helping to reduce our carbon emissions from transport. - Description added by: David Lockie