activities,particular ly by increases of sulfates, organic
condensates and soot [2–4]. Although the
interactions of aerosols with radiation have been
known for a long time [5,6], it is only recently that
the possible role of atmospheric aerosols in a
global change scenario has been considered. The
warming/cooling effects of aerosols can be separated
into the direct effects by scattering and absorption
of solar radiation and the indirect effects
by passing through cloud formation. The magnitude
of the aerosol radiative forcing is quite uncertain.
IPCC estimates that the cooling effect by
aerosols may be comparable to the warming effect
by greenhouse gases [1].