Since the mid-1970s, glaciers have been melting faster than any other point in geologic history. James Balog, National Geographic Society photographer, has visited many of the world's most stunning glaciers, and has documented their unnaturally rapid retreat as a result of global climate change. Thanks to James Balog's Extreme Ice Survey, you can go to what was once the highest ski resort in the world, Chacaltaya Glacier in Bolivia, at 17,200 ft; this thousand year old glacier has all but disappeared in the past 68 years. Or visit Columbia Glacier in Alaska, which has deflated and thinned approximately 1200 feet since the early 1980's—equivalent height to the Empire State Building. Watch time-lapse photography of many glaciers' movements around the globe, from Alaska to Greenland to Switzerland.

Through books, films, TV shows, and now through Google Earth, efforts are being made to illustrate what is going on with the world's most remote and inaccessible glaciers. "I think science and art both have something to say to the public about what's going on. And that's what motivates me. I think with these tools we have a mechanism for telling the truth and bringing the evidence to the public," said James. 

According to the Extreme Ice Survey, glacial retreat isn't happening at a glacial pace. You can watch PBS's NOVA special on Extreme Ice this Tuesday at 8pm to hear more about it. Until then, explore the Google Earth layer created by Bryce Tugwell.