Perturbation of the EarthΓÇÖs radiative budget due to scattering and absorption of solar and terrestrial radiation by aerosols is called direct aerosol radiative forcing. In major industrialized regions, the radiative forcing of climate by anthropogenic sulfate aerosols has been calculated to exceed in magnitude the forcing by anthropogenic carbon dioxide, although the signs of the two forcings are opposite.
Consequently, much attention has been given in recent years to improving the model calculations of the direct aerosol radiative forcing, and to quantifying the uncertainties of the estimates. At present, there is a great need for observational data on aerosols relevant to aerosol forcing of climate.
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The images at left are from the book titled Aerosol Forcing of Climate, edited by R. J. Charlson and J. Heintzenberg, John Wiley & Sons, 1995.
Aerosol cooling: July mean geographic distribution of direct radiative forcing by anthropogenic sulfate aerosols; highest cooling is shown in blue.
Greenhouse gas warming: July mean geographic distribution of radiative forcing due to anthropogenic greenhouse gases; greatest warming shown in red and yellow.
Net cooling/warming: July net radiative forcing due to greenhouse gases and sulfate aerosols; warming shown in red and yellow, cooling shown in white and blue.
