It's an article about the Milanankovitch Theory http://en.wikipedia.org/wiki/Milankovitch http://en.wikipedia.org/wiki/Milankovitch which theorizes that ice ag

It's an article about the Milanankovitch Theory http://en.wikipedia.org/wiki/Milankovitch http://en.wikipedia.org/wiki/Milankovitch which theorizes that ice ages are caused by cycles in the eccentricity, axial tilt, and precession of the earth's orbit. The Wikipedia article cites some problems with the theory. There are other theories. One I like is that ice ages are caused by global warming. The arctic ocean becomes ice free leading to increased evaporation and water from the melting Greenland ice cap shuts off the gulf stream, resulting in lots more snow and big glaciers. [citation needed] And maybe it's variations in the the sunspot cycle, the Maunder Minimum, but bigger.