Evolution of Earth's atmosphere

Earth's atmosphere evolved over billions of years, beginning with a mix of gases released from volcanic activity. This early atmosphere was mostly hydrogen and helium, but as volcanic eruptions continued, gases like carbon dioxide, ammonia, and water vapor became prevalent. Life emerged, particularly photosynthetic organisms, which converted carbon dioxide into oxygen. Over time, oxygen levels increased, leading to the formation of the ozone layer that protects the planet from harmful radiation. Today, the atmosphere is primarily nitrogen and oxygen, supporting diverse life forms and regulating Earth's climate.