A Description of the Disappearing Glaciers

I was reading a travel account of the Rhone glacier in the Alps:

The rocks are grooved and scarred away up hundreds of feet above the ice, showing that the glacier was once many times its present size. It is slowly melting away--dying, the scientists say. It may not last more than five or six thousand years longer, so if you want to see it you'll have to hurry.

Okay, evidence of global warming? Well, perhaps, but this account predates the enormous increase in man's production of carbon dioxide. It is from Leander A. Bigger, Around the World: An Illustrated Trip for Education and Pleasure (New York: Lyceum Travel Bureau, 1916), 3:99, describing a round the world trip of 1904-05.