Are fossil fuels considered renewable or nonrenewable sources of energy?

Fossil fuels are considered nonrenewable sources of energy because they are formed over millions of years from the remains of ancient plants and animals. Once extracted and consumed, they cannot be replenished within a human timescale. This means that as we use fossil fuels for energy, they diminish and will eventually run out. Unlike renewable energy sources, such as solar or wind power, which can be naturally replenished, fossil fuels take an extensive amount of time to form, making them finite. Therefore, once the existing reserves are depleted, they cannot be easily replaced, emphasizing their classification as nonrenewable energy sources.