If you live in the Puget Sound area, show your students the maps of maximum ice coverage of the Cordilleran ice sheet during the Pleistocene. Then go outdoors and visualize the ice and how high it would have been above you at your location. In the Seattle area, at maximum, the ice was just under 1,000 meters thick; in Bellingham, about 1,500 meters thick.
Ask your students to visualize the area 15,000 years from now. Will there be an ice sheet or something else?