  For an effective treatment of the evaporation process of a large black hole
the problem concerning the role played by the fluctuations of the (vacuum)
stress tensor close to the horizon is addressed. We present arguments which
establish a principal relationship between the outward fluctuations of the
stress tensor close to the horizon and quantities describing the onset of the
evaporation process. This suggest that the evaporation process may be described
by a fluctuation-dissipation theorem relating the noise of the horizon to the
black hole evaporation rate.
