Carbon dioxide is normally found on Earth in the gaseous state. At standard temperature and pressure (room temperature and atmospheric pressure), carbon dioxide exists as a colorless, odorless gas
. It is present in the atmosphere as a trace gas, making up about 0.04% of the air
. Solid carbon dioxide, known as dry ice, only forms at much lower temperatures (below −78.5 °C or −109.3 °F) and does not exist as a liquid at normal atmospheric pressure; it sublimates directly from solid to gas
. Therefore, under normal Earth conditions, carbon dioxide is found as a gas
