What are 5 examples of fossil fuels?

The five common fossil fuels include coal, oil, natural gas, oil shale, and combustible ice. Coal is formed from the remains of ancient plants through long-term geological processes such as peatification and lignitization, and is an important component of the traditional energy system; oil originates from the remains of plankton and algae in oceans or lakes, forming liquid hydrocarbons through geological compression and thermal cracking, and is widely used in transportation fuels and chemical feedstocks; natural gas, mainly composed of methane, is often associated with oil, emits relatively low carbon when burned, and is a common choice for power generation and residential energy; oil shale is a sedimentary rock containing combustible organic matter, from which shale oil can be extracted through dry distillation; combustible ice is found in deep-sea or permafrost regions, formed by the combination of methane and water under high-pressure and low-temperature conditions, and is a potential fossil energy source with substantial reserves. These fossil fuels are all non-renewable resources, and their formation process takes millions to hundreds of millions of years. With the advancement of the global energy transition, renewable energy is gradually becoming a key alternative to fossil fuels.