The fossils of ancient marine organisms have also created the planet's crude oil ja natural gas deposits. The marine organisms that have sunk in the seafloor have transformed into oil and gas in the high underground pressure. This process has taken millennia. Crude oil is mostly drilled from inside the ground. Because the planet's oil and gas deposits are limited, people have had to search for these fossil fuels from even more difficult locations. Oil drilling rigs make it possible for us to drill oil from the seafloor. 

All of the crude oil that is drilled from the ground is not used as a fuel. It is also used to produce plastics, glues and paints.

Coal is a fossil fuel that has been formed from ancient plants that have become caught in high underground pressures. These plants have transformed into coal over the course of hundreds of millions of years. 

Coal is mined from deep underground. It is mostly used as a fuel and as a raw material in the chemical industry. 

The gathering, refining and use of fossil fuels such as oil and coal is harmful for the planet. When burned, they release large amounts of carbon dioxide into the atmosphere. This accellerates the planet's natural greenhouse effect and contributes to global warming. This is why the use of oil and coal has to be reduced. 

Coal is mined from deep under the ground.