The ozone layer is a region of Earth's stratosphere that contains a high concentration of ozone (O3) molecules. It is located about 10 to 30 miles above Earth's surface and acts as a protective shield, absorbing the majority of the Sun's harmful ultraviolet (UV) radiation. This absorption is crucial for life on Earth, as excessive UV radiation can lead to skin cancer, cataracts, and other health issues, as well as damaging ecosystems.
The presence of the ozone layer is the result of chemical reactions between solar ultraviolet radiation and molecular oxygen (O2) in the atmosphere. When UV light strikes O2 molecules, it splits them into individual oxygen atoms, which can then react with other O2 molecules to form ozone (O3). The balance between the creation and destruction of ozone is influenced by various natural and human-made factors.
The ozone layer plays a critical role in protecting living organisms and maintaining the stability of ecosystems by filtering out harmful UV radiation. Over the decades, human activities, especially the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances, have led to thinning of the ozone layer in certain areas, particularly over Antarctica, resulting in the well-known "ozone hole." International efforts, such as the Montreal Protocol, have aimed to curb the use of these harmful substances to protect and restore the ozone layer.