OCEAN ACIDIFICATION

Question 1

Identify the control variable and planetary boundary for ocean acidification.

Answer 1

• Control Variable: Carbonate ion concentration
• Planetary Boundary: ≥80% of the pre-industrial aragonite saturation state of mean surface ocean

Question 1

Explain how the ocean acidification boundary is linked with the climate change and biosphere integrity boundaries.

Answer 1

• Ocean acidification is a consequence of increased atmospheric CO2, primarily caused by human activities. The interconnection lies in the carbon cycle, where excess CO2 leads to both climate change and negatively impacts marine ecosystems, affecting biosphere integrity.

Question 2

Describe carbon dioxide dissolution and solubility in the context of the ocean carbon system.

Answer 2

• CO2 dissolves in seawater, forming carbonic acid (H2CO3). The dissolved CO2 (pCO2) affects the balance of carbonate ions, impacting the ocean’s pH. The solubility of CO2 in seawater is a critical factor in the ocean carbon system.

Question 3

Explain how the ocean carbon system buffers the ocean against rapid changes in seawater pH.

Answer 3

• The ocean carbon system acts as a buffer through the solubility cycle. When CO2 increases, it reacts with water to form carbonic acid, but this acid is partly neutralized by the dissolution of carbonate minerals, helping mitigate drastic pH changes.

Question 4

Describe geographic differences in ocean acidification using maps.

Answer 4

• Maps show variations in ocean acidification levels globally. Some regions exhibit more pronounced changes in pH and pCO2 due to factors like upwelling, currents, and human activities.

Question 5

List impacts of ocean acidification on humans.

Answer 5

• Threatens Fisheries: Impacts marine organisms crucial for fisheries.
• Food Security: Poses risks to global food security as marine food chains are disrupted.
• Economic Consequences: Affects industries relying on marine resources.

Question 6

List solutions to the ocean acidification issue.

Answer 6

• Restoring Land Uses: Enhancing CO2 uptake by vegetation and soils.
• Geoengineering (Caution): Exploring methods like ocean fertilization cautiously.
• Reducing Fossil Fuel Emissions: Primary solution to address the root cause.