Anyone who has tossed a log on a campfire has witnessed energy changing forms, from dead organic matter to heat.
Ironically, whether you’re using a beam of light through a magnifying glass, tree branches or a splash of gasoline, your campfire’s fuel technically originated with the sun.
The key difference, however, is that all these energy sources came to be through vastly different geological paths, which attaches different consequences to their use.
What Are Fossil Fuels?
In the case of a fossil fuel — typically coal, oil and natural gas — it took tens of millions of years to take its form.