A graphical representation of the combined effects of the precession of the equinoxes, the obliquity of the ecliptic, and the eccentricity of the Earth's orbit, which was calculated early in this century by Milutin Milankovitch (1879–1958) and used to account for the variations of climate during the ice ages. Theoretically, each period of radiation minimum caused an ice age. There were nine minima in all, with an irregular spacing pattern, and each of them caused an ice advance. The three factors coincided about 13 000 years bp, at the start of the Older Dryas.
Subjects: Ecology and Conservation.