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 word 'offsetting' simply means 'compensating for'. 'Carbon offsetting' means compensating for carbon dioxide (CO2) that's being generated. We need to compensate for CO2 because of the threats posed by climate change.

Realistically, no-one can expect people to cut out absolutely everything they do that leads to CO2 emissions. We all can - and must - reduce the CO2 we're responsible for, but offsetting means we can compensate for the CO2 we can't avoid creating. Carbon offsetting schemes work by reducing CO2 that would otherwise be created, or by removing existing CO2 from the atmosphere.

And who benefits from the carbon offsetting? Who gets compensated? The answer is Planet Earth - and absolutely everyone and everything that lives on it. - Description added by: David Lockie

Renewable and alternative energy sources are set to play an increasingly important role in providing the electricity, heat, cooling and fuels that society needs. There is a wide range of energy sources such as solar (both photovoltaic and solar thermal), wind, bio-fuels and biomass, hydro-electric, geothermal and heat pumps. - Description added by: David Lockie