Venus's atmosphere is primarily composed of carbon dioxide (96.5%) and nitrogen (3.5%). While volcanic activity has contributed to the planet's atmosphere throughout its geological history, it is not the main source of Venus's current atmospheric composition. The vast majority of Venus's atmosphere is thought to have outgassed from the planet's interior early in its history, during a period of intense volcanic activity. This process is believed to have been responsible for the formation of Venus's thick carbon dioxide atmosphere. Although Venus continues to experience some volcanic activity, it is not significant enough to have a major impact on the planet's overall atmospheric composition.