Effective radiative forcing কী?

The effective radiative forcing (ERF) of a perturbation — a change in a greenhouse gas, in aerosols, in the Sun — is the change it causes in the net downward flux of radiation at the top of the atmosphere, in $\mathrm{W}\,\mathrm{m}^{-2}$, once the atmosphere, the clouds and the land surface have adjusted to it, but before the global surface temperature has responded. The adjustments counted are those caused by the agent itself, independently of the surface temperature.