If you look at this graph in detail, you
can see that the retreat in the period 1929-1953 (24 years) was faster
than in 1953-2003 (50 years).
Thus all together, the retreat of Greenland ice is the result of global
warming at least since 1850, and the retreat was faster around
1930-1940 than today, when GHGs were not playing any important role.
Moreover, the summer temperatures
around Greenland in recent years (still) are slightly less than in the
Btw, this glacier is one of the most impressive parts of Greenland, see
there in 2000...