For the last 40 years the UK has used over 70 million tonnes of oil every year, much of this in the manufacture of petrol ("gasoline") and diesel fuels. Forecasts suggest that, at the current rate of use, oil will begin to run out globally some time in the middle of this century. It is clearly vital that alternatives are developed sooner rather than later.
As reserves become limited to a smaller number of countries, it will become more important for other countries to find alternative sources of energy and feedstock, and oil may well become less important as a resource. After all, as has been observed, the Stone Age did not end because of a shortage of stones
Combustion of hydrocarbons should produce carbon dioxide and water. The use of petrol and diesel leads to several other emissions as well: