interglacial cycles as represented by atmospheric
CO2, measured from ice core samples going back 800,000 years. The stage names are part of the North American and the European Alpine subdivisions. The correlation between both subdivisions is tentative.
Quaternary, which started about 2.6 million years
before present, there have been a number of glacials and interglacials. At least eight glacial cycles have occurred in the last 740,000 years alone.
The Penultimate Glacial Period (PGP) is the glacial period that occurred before the
Last Glacial Period. It began about 194,000 years ago and ended 135,000 years ago, with the beginning of the
Since orbital variations are predictable, computer models that relate orbital variations to climate can predict future climate possibilities.
Berger and Loutre suggests that the current warm climate may last another 50,000 years. The amount of heat trapping (greenhouse) gases being emitted into the Earth's oceans and its atmosphere may delay the next glacial period by an additional 50,000 years.
^Christopher M. Fedo; Grant M. Young; H. Wayne Nesbitt (1997). "Paleoclimatic control on the composition of the Paleoproterozoic Serpent Formation, Huronian Supergroup, Canada: a greenhouse to icehouse transition". Precambrian Research. Elsevier. 86 (3–4): 201.
^Miriam E. Katz; Kenneth G. Miller; James D. Wright; Bridget S. Wade; James V. Browning; Benjamin S. Cramer; Yair Rosenthal (2008). "Stepwise transition from the Eocene greenhouse to the Oligocene icehouse". Nature Geoscience. Nature. 1 (5): 329.