Climate change has transformed our world, but the effects aren't instantaneous, making it difficult to fully grasp the severity of the situation. One way to demonstrate the detrimental impact that global warming has on the environment is through "repeat photography," or the act of comparing recent images with ones taken long ago. Since 1997, the U.S. Geological Survey has been shooting the Repeat Photography Project, with a systematic search of the archives at Glacier National Park in Montana and Alaska. They use images from the late 1800s and early 1900s as references and rephotograph the same glacial scenes to show just how much these places have changed.
So far, photographers have taken over 60 images that feature 17 different glaciers. Thirteen of them have shown a marked recession, and some are just one-third of their estimated maximum size, which peaked around 1850–and sadly, only 26 named glaciers still exist of the 150 that were present back then. Looking at the comparative images, the difference is striking, a somber reminder of the toll that these rising temperatures have taken.
National Geographic created a short three-minute film about the project, focusing on the park in Montana. Check it out, below.
Chaney Glacier, Glacier National Park, Montana: 1911 (Top) and 2005 (Bottom)
Sperry Glacier, Glacier National Park, Montana: circa 1930 (Top) and 2008 (Bottom)
Grinnell, Gem, and Salamander Glaciers, Glacier National Park, Montana: 1910 (Top) and 2012 (Bottom)
Shepard Glacier, Glacier National Park: 1911 (Top) and 2005 (Bottom)
Jackson Glacier, Glacier National Park: 1911 (Top) and 2009 (Bottom)