Readers learn that the ozone layer prevents the sun’s harmful rays from reaching the Earth’s surface and how it is already thin in certain places. Readers investigate the causes of the thinning of the ozone layer, and some of the consequences–skin cancer, destruction of crops, and harm to marine life. They also learn about the link between the ozone layer and increased global warming that could lead to climate change. The book provides a solid background on the specific environmental factors of exposure to excess UV radiation and the physical and mental effects on people. The final chapter explains what readers can do to protect the ozone layer, including preventing the release of more chemicals that harm it.