the carbon cycle
noun [ S ] biology, environment specialized uk/ˈkɑː.bən ˌsaɪ.kəl/ us/ˈkɑːr.bən ˌsaɪ.kəl/
碳循环（生物之间或生物与环境之间的碳物质交换，主要途径有生物的光合作用、呼吸作用、腐烂降解及化石燃料的燃烧）
the continuous movement of carbon between different living organisms on earth and between living organisms and the environment, through natural processes like photosynthesis, respiration, and decomposition in the soil, and also the burning of fossil fuels