What are variable gases in the atmosphere?

Variable gases in the atmosphere refer to gases that can fluctuate in concentration due to natural processes and human activities. Methane and ozone are excellent examples of variable gases.

Methane, for instance, is produced by biological processes, such as digestion in ruminant animals, and from industrial activities, leading to variations in its concentration. Ozone, on the other hand, exists in varying quantities at different altitudes, significantly affected by both seasonal changes and pollution.

The significance of variable gases lies in their impact on climate and atmospheric chemistry. For example, methane is a potent greenhouse gas that greatly affects global warming potential, while ozone plays a crucial role in absorbing harmful UV radiation in the stratosphere and acts as a pollutant at ground level.

In contrast, the other choices, such as nitrogen and oxygen, are predominant and relatively constant gases in the atmosphere, making them examples of major or permanent gases rather than variable gases.