What's a dinosaur doing in my gas tank?

Right now, most of the energy we use around the world comes from fossil fuels or petroleum. Fossil fuels are found deep under the ground and come from the ancient fossils of plants and dinosaurs that lived on earth millions of years ago. Some common fossil fuels are gasoline, oil, coal, and natural gas. We use fossil fuels to drive cars and trucks, heat our homes, make electricity, and run factories.

Fossil fuels are non-renewable, which means that nature only contains a certain amount. Once they are gone, that's it—there won't be more for us to use. It is likely we will run out of fossil fuels in our lifetimes and will need to get energy from other sources. That's why it's important to start looking for different ways to get energy before we run out of fossil fuels. These different ways to get energy are called alternative energy sources.