 |
|
|
|
|
|
|
|
|
|
|
|
|
|
| q |
The
major sources of anthropogenic aerosols are fossil fuel and
|
|
|
biomass
burning. These sources are
also linked to degradation
|
|
|
of air
quality and acid deposition.
|
|
|
| q |
In
general, the direct radiative forcing of aerosols is negative
|
|
|
(except for
black carbon fossil).
|
|
|
| q |
There is
much less confidence in the ability to quantify the total
|
|
aerosol
direct effect, and its evolution over time.
|
|
|
| q |
Aerosols
also vary considerably by region and respond quickly
|
|
|
to changes
in emissions.
|
|
|
| q |
In
addition to their direct radiative forcing, aerosols have an
|
|
|
indirect
radiative forcing through their effects on clouds.
|
|
|
| q |
There is
now more evidence for this indirect effect, which is
|
|
|
negative,
although of very uncertain magnitude.
|
|