A boy touches one of the photos displayed during the 'Extreme Ice' exhibit by US photographer James Balog at the Museum of Science and Industry in Chicago. Pics/AFP

Chicago: For the last decade, American photographer James Balog has been on a mission to document climate change through his camera lens. His effort has taken him to the farthest reaches of the world, from Antarctica to the northern ends of Greenland, where he has captured the movements and melts of immense glaciers.