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

The state of the environment in which we live is of the highest importance – without it we cannot live, and if it is not functioning normally our lives become increasingly difficult. The number of people on the planet and the accelerating rate of individual resource consumption are having negative or disruptive effects on the environment. Global warming and climate change are now global challenges attracting much media attention. Resources such as drinkable water, food and non-polluted environments are all becoming more dependent on technology and competition is growing for these resources. Thus the decisions that we need to make on our journey to becoming 'low carbon' should always be taken with environmental impacts in mind. - Description added by: David Lockie