Which process removes CO2 from the atmosphere as part of the carbon cycle?

Which process removes CO2 from the atmosphere as part of the carbon cycle?

• A. Decomposition
• B. Combustion
• C. Respiration
• D. Photosynthesis

Answer: (D)

Photosynthesis removes carbon dioxide from the air by using it, along with water and sunlight, to build organic matter like glucose. Plants and other photosynthesizers take in CO2 with their stomata, convert it into sugars, and release oxygen in the process. This makes photosynthesis the primary way CO2 is pulled out of the atmosphere and stored in living matter and soils, at least during active growth. Other processes add CO2 back into the air. Decomposition recycles carbon as organisms break down; respiration releases CO2 when plants and animals convert stored sugars for energy; combustion, such as burning fossil fuels or biomass, releases CO2 as the carbon stored in fuels is oxidized. So these activities act as sources of atmospheric CO2 rather than removing it.

Photosynthesis removes carbon dioxide from the air by using it, along with water and sunlight, to build organic matter like glucose. Plants and other photosynthesizers take in CO2 with their stomata, convert it into sugars, and release oxygen in the process. This makes photosynthesis the primary way CO2 is pulled out of the atmosphere and stored in living matter and soils, at least during active growth.

Other processes add CO2 back into the air. Decomposition recycles carbon as organisms break down; respiration releases CO2 when plants and animals convert stored sugars for energy; combustion, such as burning fossil fuels or biomass, releases CO2 as the carbon stored in fuels is oxidized. So these activities act as sources of atmospheric CO2 rather than removing it.