An increase in the extremality of natural processes is a consequence of warming, aridization, and desertification. The authors consider the processes of warming, aridization, and desertification to be the parts of a single system and major destabilizing factors of ecological balance. Destabilization is expressed in the growth of natural processes extremality. Ecosystems of Transbaikalia were once characterized by a different natural contrast and amplitude. Warming, aridization and desertification have led to an increase of environmental regimes tensions. This is demonstrated quantitatively by the root-mean-square difference of atmospheric and soil parameters. Quantitative indicators of aridization are estimated using Walter-Gossen climate charts. Permafrost zone response information to the long-term warming is provided as well.