'''Fossil fuels''' - coal, oil and natural gas, are sources of energy that are generally believed to have been formed from the remains of plants and animals that lived long ago<ref>Up to 300 million years ago according to secular geology, or during the [[Great Flood]] according to [[Flood Geology]]</ref> and are thus essentially non-renewable. | '''Fossil fuels''' - coal, oil and natural gas, are sources of energy that are generally believed to have been formed from the remains of plants and animals that lived long ago<ref>Up to 300 million years ago according to secular geology, or during the [[Great Flood]] according to [[Flood Geology]]</ref> and are thus essentially non-renewable. |