  It is well-known that active galactic nuclei (AGN) are accompanied by winds
and outflows, some of which may reach weakly relativistic speeds of about $10$
percent the speed of light. Yet, in spite of their ubiquity, the impact of AGN
outflows in modulating surface habitability of terrestrial planets on galactic
scales, using the Milky Way as the basis for comparison, is poorly investigated
and inadequately understood. In this work, we address this issue by focusing on
two key mechanisms: AGN winds can heat atmospheres and drive atmospheric
escape, as well as stimulate the formation of nitrogen oxides and thence cause
ozone depletion. By developing simple models, we estimate the maximal distance
up to which these deleterious effects are rendered significant for Earth-like
planets in the Milky Way, and thereby demonstrate that this value may extend to
$\lesssim 1$ kpc. In the case of quasars hosting larger supermassive black
holes, such effects could actually influence the AGN host galaxy as a whole.
