Fossil fuel

A fossil fuel is a hydrocarbon-containing material formed underground from the remains of dead plants and animals that humans extract and burn to release energy for use. The main fossil fuels are coal, petroleum and natural gas, which humans extract through mining and drilling. Fossil fuels may be burnt to provide heat for use directly (e.g. for cooking), to power engines (such as internal combustion engines in motor vehicles), or to generate electricity.

The principal origin of fossil fuels is the anaerobic decomposition of buried dead organisms, containing organic molecules created in ancient photosynthesis. The transitions from these source materials to high-carbon fossil fuels typically requires a geological process of millions of years, sometimes more than 650 million years.