Grinnell Glacier, Montana has been shrinking in size.

Glaciers worldwide are shrinking in size

This picture shows the Grinnell Glacier in Glacier National Park, Montana, USA in 2005. The glacier has been retreating rapidly since the early 1900's. The year markers point to the former extent of the glacier in 1850, 1937,1968, and 1981. Mountain glaciers are excellent monitors of climate change; the worldwide shrinkage of mountain glaciers is thought to be caused by a combination of a temperature increase since the Little Ice Age, which ended in the latter half of the 19th century, and increased greenhouse-gas emissions.