Remarkable time-lapse footage by one of the world's foremost nature photographers reveals massive glaciers and ice sheets splitting apart, collapsing, and disappearing at a rate that has more and more scientists alarmed. This NOVA-National Geographic Television special investigates the latest evidence of a radically warming planet. "Extreme Ice" follows National Geographic-funded photojournalist James Balog to some of the most dangerous places on Earth as he documents the disappearance of an icy landscape that took thousands of years to form. An artist, scientist, explorer, and former mountain guide, Balog braved treacherous terrain to site his cameras in ideal locations to record the unfolding frozen drama.