Gruber (2011) highlights what about oceans under climate change?

• A. Ocean biogeochemistry is affected, including acidification and oxygen loss; focus on biochemical processes.
• B. Climate change has no effect on oceans.
• C. Ocean chemistry remains stable.
• D. Gruber argues for ignoring marine systems.

Answer: (A)

Climate change reshapes how chemical and biological processes operate in the ocean. Gruber emphasizes that ocean biogeochemistry is affected in real, measurable ways: more CO2 dissolves in seawater, forming carbonic acid, which lowers pH and reduces carbonate ions. That shift, acidification, directly impacts calcifying organisms and the carbonate system that supports much of marine chemistry. At the same time, warming water lowers the ocean’s capacity to hold dissolved oxygen and strengthens stratification, which can lead to deoxygenation in deeper waters. These changes alter nutrient cycling, productivity, and ecosystem dynamics, showing that the chemical and biological fabric of the oceans is altered by climate change. The other statements—claiming no effect, stability, or ignoring marine systems—do not align with the observed and modeled responses of ocean biogeochemistry to a warming, higher-CO2 world.