Geospheric cycles constitute periodic events which occur on the scale of the planetary atmosphere, biosphere, hydrosphere, and lithosphere.
Geospheric cycles have comparatively long periods which vary according to time and distance, and include geophysical, biological, evolutionary, and cultural cycles.
Geospheric cycles are often synchronous with astronomical cycles, or with one another, which produces various phase relations between the cycles.
The interference which occurs as a result of the phase relations between cycles produces slowly shifting global patterns which interact with one another at various time rates.
Large-scale fluctuations of the geosphere are influenced by galactic, solar, and lunar cycles, and include glacial and interglacial periods, seasonal changes, oceanic tides, light-dark periods, and various evolutionary cycles such as the 26 million-year mass extinction cycle in which 90 per cent of all biological species become extinct.
In addition, cultural cycles include fluctuations of so-called golden and dark ages, periodic shifts in ideology including aesthetic, philosophical, religious, scientific, and political movements and trends, as well as regular periods of economic and commercial growth and decline.