Final answer:
Increased chlorofluorocarbons (CFCs) in the atmosphere result in more ultraviolet light reaching the Earth's surface, raising temperatures and decreasing plant populations.
Step-by-step explanation:
The increased presence of chlorofluorocarbons (CFCs) in the atmosphere leads to the depletion of the ozone layer, which acts as a shield protecting Earth from harmful ultraviolet (UV) radiation. When CFCs are broken down by UV radiation, they release chlorine atoms that catalyze the destruction of ozone molecules. With less ozone in the stratosphere, more UV radiation reaches the Earth's surface. This increase in UV exposure can have detrimental effects on vegetation growth, as it can damage plant DNA, reduce photosynthesis, and impair plant development and reproduction, ultimately leading to a potential decrease in plant populations. Therefore, the correct answer to how increased CFCs would affect vegetation growth is B: Ultraviolet light will increase on Earth's surface. It will raise temperatures and decrease plant populations.