The proposal of the "Double Carbon Target" has brought more and more attention to the emission of carbon dioxide. Today, carbon dioxide has become an air pollutant that is mainly monitored in many fields such as industrial production, agricultural breeding, and indoor environment. With the continuous development of science and technology, the improvement of people's living standards and people's increasing emphasis on environmental protection, quantitative monitoring and control of carbon dioxide gas has become a growing demand in air conditioning, agriculture, medical care, automobiles and environmental protection. Next, we will bring you knowledge about how carbon dioxide works and what kinds of it.