AP Environmental Science

Answer: B - A change in the carbon cycle could produce a climate shift in an ecosystem.

Key Takeaway: It is important to remember that carbon is the main element that exists in all living organisms. Carbon can also be found in the atmosphere, in rocks, and in the oceans. The carbon cycle generally refers to the repeating exchange of carbon (as either carbonates or carbon dioxide) between the oceans, the atmosphere, and the Earth’s rocks. Because the amount of carbon dioxide in the atmosphere is directly related to the surface temperature of the Earth, a change in the carbon cycle could definitely produce a climate shift in an ecosystem.