Fossil fuels are a finite resource. If current rates of production and consumption remain constant, the world's reserves of some fossil fuels could be exhausted before the end of the 21st century.
A number of mitigating actions are planned or already in train:
- Use energy more efficiently. Energy efficiency can help existing resources to last longer by reducing demand for energy.
- Increase the use of renewable energy sources. Unlike fossil fuels, renewable energy sources are practically inexhaustible. Improved technology could help to increase the proportion of this renewable energy resource that can be converted into useful energy.
- Increase the use of nuclear energy. Uranium – the fuel used in nuclear power stations – is not a renewable resource, but as it is a highly concentrated source of energy, the quantities required for large-scale electricity generation are smaller than for fossil fuels. New nuclear power stations are planned and the lifespan of certain existing ones could be safely extended.
- Extract unconventional fossil reserves. The increasing cost of conventional fossil fuel reserves and the development of new extraction technologies mean that unconventional fossil fuels, such as shale gas, are becoming more economically viable in some places, although uncertainty over costs and affordability remains. However, there are concerns about the environmental impact of extracting these unconventional resources.