Abstract. The cryosphere of the Earth overlaps with the atmosphere, hydrosphere and lithosphere over vast areas with temperatures below zero C and pronounced H2O phase changes. In spite of its strong variability in space and time, the cryosphere plays the role of a global thermostat keeping the thermal regime on the Earth within rather narrow limits affording continuation of the conditions needed for the maintenance of life. Objects and processes related to cryosphere are very diverse due to the following basic reasons: anomalous thermodynamic and electromagnetic properties of H2O, intermediate intensity of hydrogen bonds, and very wide spread of cryogenic systems all over the Earth. These features yet attract insufficient attention of research communities. Cryology is usually understood as a descriptive discipline within physical geography basically limited to glaciology and permafrost research. We emphasize its broad interdisciplinary landscape involving physical, chemical and biological phenomena related to the H2O phase transitions and various forms of ice. This paper aims to attract attention of readers to crucial importance of cryogenic anomalies which make the Earth atmosphere and the entire Earth system very specific, if not unique, objects in the universe.