Time-lapse photo couplets of glaciers revealing retreat. (A–B) Mendenhall Glacier, Alaska, retreat of ~550 m from 2007 to 2015. (C–D) Solheimajokull, Iceland, retreat of ~625 m from 2007 to 2015. (E–F) Stein Glacier, Switzerland, retreat of ~550 m from 2006 to 2015. (G–H) Trift Glacier, Switzerland, retreat of ~1.17 km from 2006 to 2015. (I–J) Qori Kalis Glacier, an outlet of the Quelccaya Ice Cap, Peru, retreat of ~1.14 km from 1978 to 2016. Photo credits: (A–H) James Balog and the Extreme Ice Survey; (I–J) Lonnie Thompson.