Milankovitch cycles and a variety of other phenomena such as the Earth’s other orbital mechanics, rotational precession, magnetic pole reversals, lengthening diurnal rotation (longer days), reducing lunar tidal forcings, and so forth represent much smaller and shorter influences when compared to the vastly larger changes in atmospheric mass and composition by inorganic and organic influences. There are for some examples the expression of the Milankovitch cycles in the varves of the Devonian, when the development of the first forests upon the Earth radically increased the concentration of oxygen in the atmosphere while more than halving the already trace amounts of carbon dioxide, which resulted in another major ice age and a mass extinction event. When you are doing geological field work, you can see in the varves how the water levels changed in synchronization with the Milankovitch cycles, but the far larger events ended these sequences with overwhelming changes to the geomorphology, sea levels, and related biosphere. It is always provocative to see the media go on about the Milankovitch cycles in connection to the stages of the curreent ice age while totally neglecting the many other vastly more forceful changes in the Earth’s inherent composition and solar luminosity.
Thank you for your knowledge on the subject! I was up pretty late reading all kinds of different stuff as this was the first I had heard of the Milankovitch cycles. Being an engineer and understanding that nothing is absolute and has some certain tolerance band, i.e. our orbit around the sun, the Earth’s axis tilt, it got me thinking about how these tolerances, coupled with the sunspot cycle, may have affected climate changes in the past. Your additional information is really valuable.
Its also cool that they are studying the same stuff on Mars. Kinda blows a hole in the MAN-MADE theory when man has never set foot on Mars.