There are two main sources of carbon dioxide in the atmosphere. One is a natural source, such as animal and plant respiration. During the process of metabolism, animals and plants will inhale oxygen and exhale carbon dioxide, which is a natural move to maintain life activities. The second is a human source. With the development of human society, the scale of industrial production has gradually increased. When many factories burn fossil fuels such as coal and oil, a large amount of carbon dioxide is released into the atmosphere. At the same time, in the field of transportation, fuel-powered vehicles such as cars and airplanes also emit a considerable amount of carbon dioxide during operation. These sources cause changes in the amount of carbon dioxide in the atmosphere, which has an impact on the earth's climate system.