The phenomenon being discussed that affects the shells of organisms is ocean acidification. Based on what you know about pH, do you think "acidification" refers to a decrease in pH or an increase in pH? Explain.

Why do you think that this drop in pH occurred after the Industrial Revolution? 

Explain how more carbon dioxide in the atmosphere can cause the pH of the ocean to decrease. 

Based on what you know about chemical equilibrium, what would have to occur for the acidification of the oceans to be reversed? Explain your answer.