Here's how it works:
1. Photosynthesis: Plants and other photosynthetic organisms use carbon dioxide from the atmosphere and sunlight to create sugars (food) and release oxygen.
2. Marine Organisms: Tiny marine organisms called foraminifera and coccolithophores incorporate the carbon from these sugars into their calcium carbonate shells.
3. Sedimentation: When these organisms die, their shells sink to the ocean floor. Over millions of years, these shells accumulate and are compressed under immense pressure.
4. Lithification: The pressure and chemical reactions turn the accumulated shells into limestone and chalk.
Therefore, the process of turning carbon dioxide into chalk and limestone is a natural process involving photosynthesis, biological uptake, sedimentation, and lithification.
