The document summarizes the main components of Earth's atmosphere. It states that nitrogen and oxygen make up 99% of the atmosphere, with nitrogen comprising 78.1% and oxygen 20.9%. The document also lists the minor permanent gases - argon, neon, helium, krypton and hydrogen - and their respective percentages. Additionally, it notes that the variable gases in the atmosphere include water vapor, carbon dioxide, methane and ozone, along with their typical percentage values.