Energy turns lights on and makes our TVs run. But is it harming Earth? Find out the difference between clean and dirty energy and how some forms of energy pollute the environment. Included are tips on how to waste less energy and other ways you can help save Earth.

Level 2 readers are aimed at children who are becoming more confident at reading on their own. Simple sentences and informative captions help readers understand new ideas, while key words increase readers' vocabulary.