Watching a mighty glacier recede before your eyes can be stunning.
To see something so huge rendered so ephemeral in just a simple pair of images.
These before-and-after shots serve as powerful reminders of climate change.
Warmer weather has been shrinking glaciers around the world, from the Himalayas to the American West. These latest images are part of a set released by the Geological Society of America.
But they don't show the whole story.
What happens after the "after" photo?
When glaciers melt, that water runs into streams and rivers. But here's the thing: It matters when the water moves into streams and rivers.
Glaciers work like icy time machines. In many areas, glaciers and mountaintop snowpack trap winter precipitation that would have otherwise ended up flowing downstream, eventually to the ocean. They then release it during the warmer, drier summer, helping even out river levels year-round.
But as glaciers shrink, that time machine winds down. Rivers and lakes can't depend on that meltwater.
This is a major worry in many areas, such as in the Himalayas and the many highly populated countries their glaciers feed, but in America too. In the Pacific Northwest, declining snowpack might starve the mighty Columbia River.
Shrinking rivers have their own after-effects.
We depend on rivers for much more than just drinking water. Hydroelectric dams provide 70% of the Pacific Northwest's electricity. They feed agricultural projects and provide a habitat for salmon, trout, and other creatures. We play in them and on them. All of these things could be affected.
We still have the power to head off negative changes. Transitioning to cleaner energy sources such as wind and solar means fewer climate-affecting emissions, while more judicious water usage could help head off the worst effects.