Arctic melt: "there is no precedent as far back as 1850 for the 21st century's minimum ice extent of sea ice on the pan-Arctic scale" http://onlinelibrary.wiley.com/doi/10.1111/j.1931-0846.2016....
Greenland: I haven't seen temperature numbers specifically for Greenland but it probably has to do with the medieval warm period, and we're warmer then that now. http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html