The first time derivative of the earth's orbital eccentricity function is sawtooth shaped, and closely mimics the ~100,000 yr cycles of the oxygen isotope Δ18O time series (the proxy for global ice volume change) of the last ~800,000 yr. Conversely, numerical integration of the data's variance closely reproduces the orbital eccentricity function for the same interval. Such long-lived, strong correlation does not appear to be coincidental, is consistent with the physics of ice sheets and with the time history of their advance and retreat. ¿ American Geophysical Union 1995