Q. Is the upward move of warm air good or bad for the dispersion of pollutants?
An upward movement of warm air is a natural method of dispersion of pollutants. The air near the ground is hotter for the reason that the sun heats the soil and the soil heats the air nearby. Ever since it is less dense, the warm air tends to move towards higher and colder strata of the atmosphere. Such movement assists the dispersion of pollutants.