Question

Ocean acidification is of considerable concern to environmental scientists as it could impact ocean biodiversity significantly. One of the impacts is the weakening of calcium carbonate shells in invertebrates, which releases carbon into the ocean. What describes the relationship between ocean acidification's causes and effects?
Responses
A Increased carbon dioxide levels in the atmosphere cause a decrease in ocean pH. The dissolution of calcium carbonate shells increases carbon in the ocean. This is a positive feedback loop, where the ocean's pH will continue to drop.Increased carbon dioxide levels in the atmosphere cause a decrease in ocean pH. The dissolution of calcium carbonate shells increases carbon in the ocean. This is a positive feedback loop, where the ocean's pH will continue to drop.
B Decreased carbon dioxide levels in the atmosphere cause a decrease in ocean pH. The dissolution of calcium carbonate shells increases carbon in the ocean. This is a negative feedback loop, where the ocean's pH will return to homeostasis.Decreased carbon dioxide levels in the atmosphere cause a decrease in ocean pH. The dissolution of calcium carbonate shells increases carbon in the ocean. This is a negative feedback loop, where the ocean's pH will return to homeostasis.
C Increased carbon dioxide levels in the atmosphere cause an increase in ocean pH. The dissolution of calcium carbonate shells increases carbon in the ocean. This is a positive feedback loop, where the ocean's pH will continue to increase.Increased carbon dioxide levels in the atmosphere cause an increase in ocean pH. The dissolution of calcium carbonate shells increases carbon in the ocean. This is a positive feedback loop, where the ocean's pH will continue to increase.
D Decreased carbon dioxide levels in the atmosphere cause a increase in ocean pH. The dissolution of calcium carbonate shells increases carbon in the ocean. This is a negative feedback loop, where the ocean's pH will return to homeostasis.

Answer 1

A.

Increased atmospheric CO2 dissolves in seawater to form carbonic acid, lowering ocean pH. Lower pH accelerates dissolution of calcium‑carbonate shells, releasing dissolved inorganic carbon into the ocean, which can drive further acidification—a positive feedback (with the caveat that some local dissolution can transiently buffer acidity, the overall feedback tends toward more acidification).