One layer of the stratosphere, the second layer of the Earth's atmosphere, is the ozone layer. The stratosphere is a layer of protecting gases that adheres to the surface of our planet. The stratosphere takes its name from the fact that it is stratified, or layered, with the stratosphere becoming warmer as elevation rises. Because ozone gases in the top layers absorb powerful UV energy from the sun, the stratosphere becomes warmer as it rises. Ozone is a trace gas in the atmosphere, accounting for just around 3 molecules per 10 million molecules of air. However, it serves a vital purpose. The ozone layer, like a sponge, absorbs solar radiation that reaches Earth. While we require some of the sun's radiation to survive, too much of it can harm living things. The ozone layer protects life on Earth by acting as a shield. Ozone is effective at trapping ultraviolet radiation, often known as UV light, which can penetrate organisms' protective layers, such as skin, and damage DNA molecules in plants and animals. UVB and UVA are the two main kinds of UV light.