二氧化碳循环

The illustration displays the cycle of carbon in the environment. Overall, carbon naturally cycles through the ecosystem via plants, animals, and the ocean. Human activity, however, may be altering the process.

Carbon dioxide in the air is absorbed by the ocean waters and vegetation on earth. Both terrestrial and aquatic plants use CO2 together with sunshine to produce food for themselves via photosynthesis. Organic carbon enters the ground in two ways. The first is through waste matter from flora and fauna, while the second is when the bodies of dead organisms decay. Furthermore, trees and plants send carbon dioxide into the soil through root respiration. Carbon-based remains that stay buried deep underground for a very long time may eventually become fossils or fossil fuels (coal, natural gas, and oil).

Carbon dioxide is returned into the air when both plants and animals respire. Human activities that utilize fossil fuel, such as manufacturing and modern travel, add to the CO2 in the atmosphere because of emissions. Then the carbon cycle begins again.