Marine scientists investigated how rising atmospheric carbon dioxide ($CO_2$) emissions affect oceanic pH and coral calcification rates across four oceanic survey stations over a 30-year observation period.
Decade
Atmospheric $CO_2$
Ocean pH
Calcification Rate
1990
354 ppm
8.25 (Normal)
1.42 g/cm²/yr
2000
369 ppm
8.18 (Mild)
1.28 g/cm²/yr
2010
389 ppm
8.11 (Moderate)
1.05 g/cm²/yr
2020
414 ppm
8.04 (Acidic)
0.74 g/cm²/yr
Writing Prompt (Tier B/C Integrated Standard):
Write a formal 3-paragraph scientific report for the Environmental Protection Board.
Paragraph 1 (Claim & Trend): State the mathematical correlation between atmospheric $CO_2$, ocean pH, and calcification rates.
Paragraph 2 (Biochemical Mechanism): Explain why adding $CO_2$ acidifies water and dissolves carbonate ions.
Paragraph 3 (Ecological Impact & Recommendation): Predict the trophic consequences if calcification drops below 0.50 g/cm²/yr and recommend an evidence-based conservation policy.