In this paper we continue discussion on the long-term variability of the ozonosphere. We consider natural factors causing the behavior of the ozonosphere. Reconstruction of paleobehavior of the ozonosphere over Arosa station in Switzerland has made it possible to predict future variations of the ozone layer for a period of several years. According to the prediction the decrease of TOC in the last quarter of the 20th century does not exceed the level of natural variations of the ozonosphere in the past, and the present-day state of the "unperturbed" ozonosphere does not contradict the period of phase change of long-term variations. In support of this statement the time behavior of TOC is given in the form of deviations from the long-term mean over Tomsk from 1996 to 2002, which is characterized by a statistically insignificant near-zero trend.