Dry Ice

I went for a walk on the glacier.

I said to the glacier, "Do you ever get bored?"

The glacier said, "Occasionally. What I end up doing is waiting till midnight when everyone is sleeping, then I melt, evaporate, catch some wind and travel to and rain on New York City. Then I go through the reverse process and come back by sunrise."

I slipped and slid down the length of the glacier. I ended up on the grass below.