A lot of our energy comes from non-renewable sources such as coal, oil and gas. These resources are made up from the remains of ancient animals and plants that develop over millions and millions of years, deep beneath the ground into what we call fossil fuels.

Fossil fuels are burned by power stations to produce electricity as well as in things like cars, planes, and steam trains.

But non-renewable resources generate harmful greenhouse gases that damage the habitats of animals and plants and contribute to global warming. And our increasing demand for energy means they won't last forever so we need to look for ways to make renewable and sustainable energy resources. For example, wind, solar and hydro energy. These are just some of the resources that are more friendly towards the environment. These renewable energy resources can quickly replenish themselves and can be used again and again.