A lot can happen in 100 years. A lot. Just look at the current state of the Arctic glaciers now compared with what they looked like roughly 100 years ago. Seriously. If this doesn't get you concerned about the environment, nothing will.
Christian Aslund, a Swedish photographer who works with Greenpeace, compiled a collection of images taken in Svalbard during the early part of the 20th century and positioned them alongside his own group of images taken in the same location.
The shocking photos are being used to promote National Geographic's #MyClimateAction campaign. The campaign itself is aiming to raise awareness about climate change, and to encourage protest against oil drilling in the melting Arctic.