Phytoplankton is a term used to describe microscopic plants living in the upper sunlit layer of the ocean. These tiny plants are responsible for much of the photosynthesis that takes place on Earth. Recent research has shown that, as the climate warms, phytoplankton growth rates go down. How might this affect photosynthesis and carbon dioxide levels? A. Less phytoplankton means less photosynthesis and lower carbon dioxide levels. B. Less phytoplankton means more photosynthesis and higher carbon dioxide levels. C. Less phytoplankton means less photosynthesis and higher carbon dioxide levels. D. Phytoplankton growth rates would not affect photosynthesis or carbon dioxide levels.