Which two processes reduce the amount of carbon dioxide (\(\mathrm{CO_2}\)) in the atmosphere?

• A. Respiration and combustion
• B. Decomposition and volcanic activity
• C. Photosynthesis and fossil fuel burning
• D. Photosynthesis and ocean absorption

Answer: (D)

Verified step by step guidance

1. Understand the role of carbon dioxide (\(\mathrm{CO_2}\)) in the atmosphere and identify processes that either add or remove \(\mathrm{CO_2}\).
2. Recall that photosynthesis is a biological process where plants, algae, and some bacteria use sunlight to convert \(\mathrm{CO_2}\) and water into glucose and oxygen. This process reduces atmospheric \(\mathrm{CO_2}\).
3. Learn that ocean absorption refers to the process where \(\mathrm{CO_2}\) dissolves into seawater. Oceans act as a carbon sink, reducing the amount of \(\mathrm{CO_2}\) in the atmosphere.
4. Contrast these processes with respiration, combustion, decomposition, and volcanic activity, which release \(\mathrm{CO_2}\) into the atmosphere rather than reducing it.
5. Conclude that photosynthesis and ocean absorption are the two processes that effectively reduce atmospheric \(\mathrm{CO_2}\) levels.