ozone layer
The stratosphere contains a layer of ozone gas. Ozone consists of three oxygen atoms O 3 . The ozone layer absorbs high-energy UV radiation. As you can see in Figure below , UV radiation splits the ozone molecule. The split creates an oxygen molecule O 2 and an oxygen atom O . This split releases heat that warms the stratosphere. By absorbing UV radiation, ozone also protects Earths surface. UV radiation would harm living things without the ozone layer.