Fossil Fuels

An extracted and burnt fossil fuel is a hydrocarbon-containing substance that naturally originated in the Earth's crust from the remnants of extinct plants and animals. Coal, unrefined oil, and natural gas are the three primary fossil fuels. Fossil fuels can be used to produce energy, power engines (like internal combustion engines in cars), or supply heat for immediate use (such for cooking or heating). Before burning, certain fossil fuels are processed to produce derivatives like kerosene, gasoline, and propane. The anaerobic decomposition of buried deceased animals that contained organic molecules produced by photosynthesis is the source of fossil fuels. The geological process that transforms these elements into high-carbon fossil fuels often takes millions of years. In 2019 fossil fuels accounted for 64% of the world's power and 84% of its primary energy usage. Fossil fuel combustion on a wide scale has a negative impact on the environment. Burning them results in the production of over 80% of the carbon dioxide that humans produce—roughly 35 billion tonnes year against 4 billion from land expansion. Only a limited portion of this may be eliminated by Earth's natural processes, mostly oceanic absorption. As a result, there is a yearly net increase in atmospheric carbon dioxide of several billion tonnes. Although methane leaks are significant, burning fossil fuels is the main source of greenhouse gas emissions that cause global warming and ocean acidification.