The coldest areas of the planet where water and soil are frozen—called the cryosphere--are changing rapidly. Sea ice cover is shrinking in area at rates as high as 10% per decade in the Arctic and has thinned 40% in a half century. Continued loss of the pack ice will radically alter the economic and ecological landscape of the Arctic. Sudden accelerations of ice flow by 100s of percent in just a few years at the edges of the thick Greenland and Antarctic ice sheets have surprised experts and forced revision of glacier flow processes to make them more sensitive to climate. Predictions of the consequent rise in sea level worldwide continue to lag behind reality. Snowcover is melting sooner in spring diminishing the amount of this precious resource available to water-sensitive communities during critical summer months. All this is evidence that we are moving rapidly toward a warmer climate with less ice. The exact path we take is still uncertain and an issue of increasing urgency.