How does climate change influence the Carbon Compensation Depth (CCD) and its impact on marine organisms?

1. Increased ocean acidification due to rising CO₂ levels causes CCD to become shallower.

2. Warming oceans decrease calcium carbonate solubility, pushing CCD to deeper depths.

3. A shallower CCD increases the dissolution of calcium carbonate shells, threatening organisms like foraminifera and pteropods.

Select the correct answer:

The correct answer is Option 2 

Key Points

• Increased ocean acidification due to rising CO₂ levels lowers the pH of seawater, increasing the solubility of calcium carbonate (CaCO₃). This causes the CCD to become shallower because carbonate dissolves at higher levels in the ocean. Hence, Statement 1 is Correct.
• Warming oceans actually increase calcium carbonate solubility in deeper waters by reducing CO₂ solubility, leading to higher carbonate ion concentrations. However, this effect is secondary compared to acidification, which dominates in pushing the CCD shallower, not deeper. Hence, Statement 2 is incorrect.
• A shallower CCD means that calcium carbonate dissolves at shallower depths, affecting marine organisms such as foraminifera, coccolithophores, and pteropods, which rely on CaCO₃ for their shells. This disrupts marine food chains and biodiversity. Hence, Statement 3 is Correct.
• Hence, Only 2 statements are correct (Statements 1 & 3).