19th century tourists watching a devastated Alaskan glacier collapse.
Between 1794 and 1879, the glacier at Glacier Bay, Alaska retreated eight feet per day. This was probably due to something which Sarah Palin’s great-great-great-great-great-great-grandfather did.
http://soundwaves.usgs.gov/2001/07/glacierbaymap.gif
We now know that reducing CO2 levels to 350 ppm will cause glaciers to stop melting.
The eight feet per day had nearly doubled to a mile a year by 1912:
“An investigation by the Alaska Boundary surveyors has disclosed the fact that the Great Glacier, which is situated on Glacier Bay, is receding at the rate of a mile a year, according to measurements taken on the open water”
~14 Sept 1912
http://trove.nla.gov.au/ndp/del/article/10514299?