How does the level of atomic chlorine affect ozone in the stratosphere?

The correct answer highlights an important aspect of atmospheric chemistry, particularly regarding the role of chlorine in stratospheric ozone depletion. Chlorine atoms, which can come from man-made compounds like chlorofluorocarbons (CFCs), have a high reactivity with ozone (O3) molecules. When chlorine is present in the stratosphere, it can catalyze reactions that break down ozone, leading to a decrease in its concentration.

Specifically, one chlorine atom can destroy thousands of ozone molecules before it is removed from the atmosphere. This catalytic cycle indicates that as the level of atomic chlorine increases, the level of ozone decreases as a result of the ongoing reactions that deplete ozone more rapidly than it can be naturally replenished.

This relationship is crucial in understanding how anthropogenic activities can influence atmospheric composition and environmental health. Therefore, the increase in chlorine correlates strongly with a decrease in ozone levels, which is why the choice correctly reflects the impact of chlorine on stratospheric ozone.