Ozone exists in two distinct layers of the atmosphere, resulting in two fundamentally different types: "good" ozone and "bad" ozone. These classifications depend entirely on their location and impact.
1. "Good" Ozone (Stratospheric Ozone)
- Location: Found in the stratosphere, a layer of the atmosphere extending from about 10 to 50 kilometers above the Earth's surface. This is where some jet planes fly.
- Role: This ozone layer acts as a crucial shield, absorbing most of the sun's harmful ultraviolet (UV) radiation, protecting life on Earth. Without it, life as we know it would be impossible.
- Impact: Beneficial for life.
2. "Bad" Ozone (Tropospheric Ozone)
- Location: Found in the troposphere, the layer closest to the Earth's surface (up to approximately 10 kilometers). This is the air we breathe.
- Formation: Formed through photochemical reactions involving sunlight and various chemicals emitted by human activities, such as vehicle exhaust and industrial emissions. It is a secondary pollutant, meaning it's not directly emitted but forms from chemical reactions in the atmosphere.
- Impact: Harmful pollutant. It can cause respiratory problems and damage vegetation. The EPA regulates ground-level ozone.
The EPA's website (https://www.epa.gov/ground-level-ozone-pollution/ground-level-ozone-basics) provides further information on ground-level ozone pollution. Several sources mention that ozone, depending on its location, is classified as "good" or "bad" ozone (https://byjus.com/question-answer/what-are-the-2-types-of-ozone/). The UNEP also highlights the dual impacts of ozone (https://ozone.unep.org/one-gas-two-very-different-impacts-people-and-environment).
