Carbon dioxide (CO₂) is a colorless, odorless gas that is naturally present in Earth's atmosphere. It is produced by the respiration of animals and plants, as well as through the combustion of fossil fuels like coal, oil, and natural gas. CO₂ plays a crucial role in the carbon cycle, where it is absorbed by plants during photosynthesis to produce oxygen. In addition to its natural sources, human activities have significantly increased CO₂ levels, contributing to climate change. This greenhouse gas traps heat in the atmosphere, leading to global warming and various environmental impacts. Monitoring and reducing CO₂ emissions is essential for maintaining a healthy planet.