Read here. This must have been extremely painful to those scientists claiming modern temperatures are "unprecedented," and had devoted a portion of their career towards fabricating "hockey stick" confirmations, as revealed by the Climategate emails.
As for what this result implies, the researchers conditionally -- and rather amusingly -- state that further warming of present day Greenland climate "will result in temperature conditions that are warmer than anything seen in the past 1400 years." But, of course, their work more directly and unconditionally implies that late 20th-century and early 21st-century weather has not yet been warm enough to confer "unprecedented" status upon Greenland air temperatures. What is more, Vinther et al. readily admit that the independent "GRIP borehole temperature inversion suggests that central Greenland temperatures are still somewhat below the high temperatures that existed during the Medieval Warm Period."
