Milankovitch

The Milankovitch Theory—Earth’s Climate through Time

Beth Caissie, Physics 212

April 16, 2003

In the nineteen-teens, as World War I raged across Europe, Milutin Milankovic, a Serbian astronomer and prisoner of war, was busy computing the gravitational force of planets like Jupiter on the Earth’s tilt and orbit. He had an idea that the amount of solar radiation that reaches higher latitudes could trigger an ice age or warm up the Earth. He believed that slow changes in the Earth’s orbit contributed to the amount of solar radiation reaching a particular latitude. By the end of the war, his first paper was published on the subject, and he began to expand upon his initial ideas. In 1941, he published Canon of Insolation of the Earth and Its Application to the Problem of the Ice Ages, describing his theories about the Earth’s orbit and tilt which are now referred to as the Milankovitch Cycles.

graphic from: http://www.museum.state.il.us/exhibits/ice_ages

There are three main tenets of the Milankovitch Theory:
• the tilt of the Earth, or its obliquity
• the ellipticity or eccentricity of the Earth’s orbit
• the precession of the equinoxes.

Milankovic’s theories were initially ignored. Then in the 1970’s, scientists showed a renewed interest, and now the Milankovitch Cycles are widely accepted as contributing to the cycles of the ice ages although they continue to be critiqued and revised.

Milutun Milankovic

image from www.ghmskola.edu.yu


Obliquity	Eccentricity	Precession	Climate Change	Critiques of Milankovitch	References