Tropospheric ozone
Also called: Ground-level ozone · Topic: Climate Change: Causes, Evidence and the Global Response · NCERT: Class 11, Ch 11 "World Climate and Climate Change"
Meaning
Tropospheric ozone is ozone in the troposphere, the lowest layer of the air, where we live. It is not released directly. It forms when pollutants from vehicles and factories react together in sunlight. Near the ground it is both a greenhouse gas and a harmful pollutant that hurts lungs and damages crops. This is the opposite of ozone in the stratosphere, which protects life.
Example
In Delhi and other big cities in the Indo-Gangetic plain, heavy traffic and strong summer sunlight produce high levels of ground-level ozone, mostly in the afternoon.
Don't confuse with
- Stratospheric ozone (the ozone layer): it is found high above the ground and blocks harmful ultraviolet rays. The same gas is useful up there and harmful down here.
- Ozone hole: this is a thinning of stratospheric ozone over Antarctica caused by CFCs. It has nothing to do with ozone pollution near the ground.
Related concepts
- Greenhouse effect
- Greenhouse gases
- Global warming potential
- Methane
- Nitrous oxide
- Chlorofluorocarbons
- Carbon sink
- Climate sensitivity
- Carbon budget