What is the Ozone Layer?

The ozone layer is a region of the upper atmosphere that contains a higher concentration of ozone molecules. It helps absorb much of the Sun's harmful ultraviolet radiation.

Why the ozone layer matters

Without the ozone layer, more ultraviolet radiation would reach Earth's surface. That could increase risks to skin, eyes, ecosystems, crops, and many living systems.

Ozone layer versus ground-level ozone

Ozone high in the atmosphere is protective. Ozone near the ground can be a harmful pollutant. The same molecule can have very different effects depending on where it is.

The ozone layer is part of the atmosphere that also helps create the visible conditions behind the blue sky.