  We address some of the issues that appear in the study of back reaction in
Schwarzschild backgrounds. Our main object is the effective energy-momentum
tensor (EEMT) of gravitational perturbations. It is commonly held that only
asymptotically flat or radiation gauges can be employed for these purposes. We
show that the traditional Regge-Wheeler gauge for the perturbations of the
Schwarszchild metric can also be used for computing physical quantities both at
the horizon and at infinity. In particular, we find that the physically
relevant components of the EEMT of gravitational perturbations have the same
asymptotic behaviour as the stress-energy tensor of a scalar field in the
Schwarzschild background, even though some of the metric components themselves
diverge.
