Radiative forcing

Summary

Radiative forcing is the change in the net flow of radiative energy into the climate system caused by an imposed change. Examples are more carbon dioxide, volcanic aerosols or a change in the brightness of the Sun. It is measured before the surface temperature has responded. It is measured in watts per square metre, averaged over the globe. It lets very different causes of climate change be compared on one scale. In simple models the eventual change of the global temperature is roughly proportional to the forcing.