Estimates from international organisations suggest that if the world's demand for energy from fossil fuels continues at the present rate, that oil and gas reserves may run out within some of our lifetimes. Coal is expected to last longer.
Fossil fuels are a finite resource. Once used they cannot be replaced.
Many pollution issues have been identified relating to fossil fuels:
Carbon emissions contribute to build-up of greenhouse gases and must be reduced if climate change is to be addressed.
With fossil fuel resources being depleted at an increasing rate and concerns about pollution, many countries have looked to other methods of energy production.
The bar chart below shows the percentages of the top 15 countries that emit CO2.