The great ice sheets of Greenland and Antarctica are shrinking faster and faster, increasing the rate of sea level rise. Observations of this accelerating ice loss have surprised the experts and confounded the predictive models that policy makers might rely on to take action. The distant future is easy to forecast—less ice on Earth—one million years of paleoclimate data say so, but more detail is needed. Direct field studies have identified a number of causes for the sudden awakening of the ice sheets. All have a common element. Those attending the lecture will learn what that common element is; it will not be revealed in this abstract. The analogue of tidewater glacier retreat casts a disheartening picture on our future that continued ice sheet mass loss may well be irreversible and will affect your life—whether you attend the lecture or not!