Images from a handheld camera on a British Expedition in 1931, which investigated the area for a potential landing strip. Photo Scott Polar Research Institute.

The ice retreat was at same level in the 1930s as it is today

By greenland today, source Nature.com
29 MAY 2012
Accordin to Nature, the International weekly journal of science, old photos of Greenland from the 1930s, discovered in Copenhagen, have allowed researchers to construct a history of glacier retreat.
Anders Bjørk at the University of Copenhagen and his colleagues, aims to provide a deeper understanding of how climate change has affected ice loss and glacier movements over the past 80 years.
The US military conducted an intensive aerial photo campaign of the Greenlandic coast in the Second World War, looking for German weather stations. Photo Natural history museum of Denmark.
Old observations
Most studies of Greenland’s glaciers have been done only since imaging satellites became available in the 1970s, so the data are relatively short-term.
1930s surveys of Greenland, compared with pictures from the Second World War and recent satellite images, make researchers able to observe changes from a period in which few glacier measurements were previously available.
Same level
Analysis of the images reveals that over the past decade, glacier retreat are similar to the period of warming in the 1930s.
However, whereas glaciers that spill into the ocean retreated rapidly in the 2000s, it was land-terminating glaciers that underwent the fastest regression 80 years ago.
Source: Nature – International weekly journal of science.
Read the story at Nature.com <here>
eastcoast Knud-Rasmussen-greenland-to 
Aerial photographs from a expedition by explorer Knud Rasmussen were used to compare historical changes in glacier fronts with those of today. Photo wikipedia.
Today the level of detail is much more precise and can be used for accurate measurement. This NASA satellite image from August 2010 shows when an »island of ice«, 251 square kilometres in size, breaking away from the Petermann Glacier. Photo NASA/MODIS.