This layer contains the majority of earths weather. These persents may vary due to pollutants in the air. The Stratosphere Contains the jet stream and ozone layer. Many of the commercial jets fly in or near this layer. The ozone layer absorbs most of the harmful ultraviolet rays and helps protect us.
Ozone holes do exist and have been linked to higher skin cancer rates in Australia.
Other areas also have holes. The mesosphere this area is where meteoroids burn up and leave a streak in the night sky. The Theromsphere includes in it both the Ionosphere and the Exosphere. The Ionosphere reflects radio waves back to the earth. The ions and dust particles also create a fabulous light show known as the aurora borealis sometimes called the northern lights.