When warm air layer traps pollution that is within the earth's surface, a temperature inversion usually takes place. In addition, at temperature inversion happens when the cold air overlays the warm air in the troposphere, which does not usually happen since warm air rises and cold air sinks by principle.
That will depend on which course you're talking about. It will be a minor role in, say, Maritime Law or Comparitive Religion, but a major one in, say, Particle Physics or Linear Algebra.
