Which statement about ozone depletion and UV radiation at Earth's surface is true?

Which statement about ozone depletion and UV radiation at Earth's surface is true?

• A. It decreases ultraviolet radiation reaching the surface
• B. It has no impact on UV radiation
• C. It increases ultraviolet radiation reaching the surface
• D. It only affects UV radiation at night

Answer: (C)

Ozone in the stratosphere acts as a shield, absorbing most of the sun’s ultraviolet radiation, especially UV-B. When ozone is depleted, less UV is absorbed, so more ultraviolet light reaches Earth’s surface, particularly UV-B. That’s why the statement about surface UV increasing with ozone depletion is true. The other ideas don’t fit because depletion does not reduce UV, it does have an impact on UV radiation, and UV exposure is a daytime phenomenon—nighttime isn’t a period when UV from the Sun is present.

Ozone in the stratosphere acts as a shield, absorbing most of the sun’s ultraviolet radiation, especially UV-B. When ozone is depleted, less UV is absorbed, so more ultraviolet light reaches Earth’s surface, particularly UV-B. That’s why the statement about surface UV increasing with ozone depletion is true. The other ideas don’t fit because depletion does not reduce UV, it does have an impact on UV radiation, and UV exposure is a daytime phenomenon—nighttime isn’t a period when UV from the Sun is present.