
65Radiatively Important Atmospheric Constituents
Air quality policies have heavily targeted the reduction of sulfur dioxide
and the components of photochemical smog in recent years. However, poli-
cies have been slowly hindered by the acceleration of warming, because they
result in the removal of the “cooling” effect of some aerosols. Despite the
efforts, smog is still a common problem in big cities and policies should be
further developed to reduce these pollutants and protect human health and
the environment.
The increasing temperature trend and the known cooling effect that some
types of aerosols have on the atmosphere have also sparked sc