Ice Sheet Lags Behind Summer Insolation Forcing
						q Under the most favorable condition (ice accumulates 0.3 meters each year), a full-size ice sheet 3000 meters thick would take 10,000 years to form. q At the 41,000-year cycle of orbital tilt, ice sheets lag behind changes in summer insolation by about 10,000 years. q At the 23,000-year cycle of orbital precession, ice sheet lags behind summer insolation by about 6,000 years. q The lag times are both about one quarter of the periods of the cycles.