Why are gases like nitrogen (N2) and oxygen (O2) not greenhouse gases, despite being gases that exist in the atmosphere?

Gases like nitrogen (N2) and oxygen (O2) are not greenhouse gases even though they exist in the atmosphere because they do not have the ability to absorb and radiate thermal infrared energy in the same way as greenhouse gases like water vapor, carbon dioxide, methane, and others. Greenhouse gases have specific molecular structures that allow them to absorb and re-emit infrared radiation, thereby trapping heat in the atmosphere and causing the greenhouse effect. Nitrogen and oxygen molecules do not have the same molecular structure, so they are not capable of performing the same function.

Gases like nitrogen (N2) and oxygen (O2) are not greenhouse gases because they do not have the ability to absorb and emit infrared radiation, which is a characteristic of greenhouse gases.

Greenhouse gases have the ability to trap heat in the atmosphere by absorbing and emitting infrared radiation. This process is known as the greenhouse effect. Greenhouse gases, such as carbon dioxide (CO2), methane (CH4), and water vapor (H2O), have specific molecular structures that allow them to absorb and re-emit infrared radiation, leading to the warming of the Earth's surface.

On the other hand, nitrogen (N2) and oxygen (O2) molecules are diatomic, which means they consist of two atoms bonded together. These molecules do not have a dipole moment, which is necessary for absorbing and emitting infrared radiation. As a result, nitrogen and oxygen are transparent to infrared radiation and do not contribute significantly to the greenhouse effect.

While nitrogen and oxygen are major components of the Earth's atmosphere, accounting for about 78% and 21% respectively, their molecular properties make them non-greenhouse gases.