BEFORE AND AFTER: Photos Show How Climate Change Is Already Melting The World's Glaciers

USGSA pair of images show the retreat of Pedersen in Alaska between 1917 and 2005.

While climate change is affecting every corner of the planet in different ways, the most striking evidence of a warming world is often captured by images of shrinking glaciers and the widespread disappearance of snow and ice.

Scientists are most concerned about how the dramatic loss of Antarctic land ice contributes to global sea level rise.

Researchers reported on Monday that the West Antarctic ice sheet is now in a state of irreversible collapse and could raise sea levels by as much as 4 feet by the end of the century.

The rapid retreat of the West Antarctic ice sheet is anecdotal of climate change-related impacts on ice around the world. Most glaciers have thinned and retreated during the last century. Some of this change is the result of natural ice dynamics, but warmer water flowing up from the deep ocean speeds up the rate of melting.

The comparison images that follow show significant changes to glaciers that have occurred over times periods that range from months to decades. The photos were collected by NASA for their "State of Flux" series and generally document effects that are related to increasing temperatures.