True or false: Nitrous oxide is a greenhouse gas.

Nitrous oxide is indeed a greenhouse gas, and it plays a significant role in contributing to climate change. As a greenhouse gas, nitrous oxide has the ability to trap heat in the atmosphere, which raises global temperatures. It is emitted through various human activities, including agricultural practices (like the use of synthetic fertilizers), fossil fuel combustion, and certain industrial processes.

The potency of nitrous oxide as a greenhouse gas is particularly noteworthy; it is substantially more effective at warming the atmosphere than carbon dioxide on a per molecule basis, often cited as being around 298 times more effective over a 100-year period. This substantial global warming potential underscores its importance within discussions about air quality and climate change.

Other options may suggest varying conditions or incorrect definitions which do not apply here, as nitrous oxide consistently acts as a greenhouse gas in any relevant discussion of its environmental impact. Thus, recognizing it as a greenhouse gas is critical for understanding its effects on air quality and climate.