Contemporary Climate Change 
6.6.2. Radiative Forcing by Aerosols
Atmospheric aerosols influence climate in two ways, directly through the reflection and absorption of solar radiation (in both the troposphere and stratosphere), and indirectly through modifying the optical properties and lifetimes of clouds (mainly in the troposphere) (Shine et al., 1995).
Estimation of aerosol radiative forcing is more complex and hence more uncertain than radiative forcing due to the well-mixed greenhouse gases (see section 6.5) for several reasons. First, both the direct and indirect radiative effect of aerosol particles are strongly dependent on the particle size and chemical composition and cannot be related to mass source strengths in a simple manner, For this reason, anthropogenic aerosols contribute between 10 and 20% of the atmospheric mass burden, yet 50% to the global mean aerosol optical depth
. Second, the indirect radiative effects of aerosols depend on complex processes involving aerosol particles and the nucleation and growth of cloud droplets. Third, most aerosols have short lifetimes (days to weeks) and therefore their spatial distribution is highly inhomogeneous and strongly correlated with their sources.
Greenhouse Gases
-Carbon Dioxide
·Sources
·Sinks
·Carbon Cycle
·Concentrations
·Equilibrium
-Methane
·Sources
·Sinks
·Concentrations
-Nitrous Oxide
·Sources
·Sinks
·Concentrations
-Halocarbons
·Sources
·Sinks
·Concentrations
-Ozone
-Other Gases
-Lifetimes
-Summary
Greenhouse Forcing
-Forcing Factors
-GWPs
-ΔF-ΔC
-1765 to 1990
-Ozone
Aerosols
-Sources & Sinks
-Forcing
·Direct
·Indirect
-Total Forcing
Climate Variations
-Surface Temp.
-Precipitation
-Other
·Stratosphere
·Cryosphere
·Atmos. Circulation
·Cloudiness
Detection
-Modelling
-Attribution
·Latitudes.
·Stratosphere
·Precipitation
·Sea Level
·Fingerprints
-When?
Future Climate
-GCM Simulations
-Feedbacks
·Water Vapour
·Clouds
·Ice Albedo
·G-house Gases
-21st Century
Impacts
-Agriculture
-Forestry
-Ecosystems
-Water Resources
-Oceans/Coasts
-Human & Health
Responses
-Stabilising
-FCCC
-Kyoto Protocol
-UK Programme
·Energy Demand
·Energy Supply
-Evaluation