An ice-melting barometer of change
As an example of the findings, the sub-report on Greenland shows a relatively dramatic 2010:
Greenland climate in 2010 is marked by record-setting high air temperatures, ice loss by melting, and marine-terminating glacier area loss.
Summer seasonal average (June-August) air temperatures around Greenland were 0.6 to 2.4°C above the 1971-2000 baseline and were highest in the west.
© 2010 J. E. Box et al., Arctic Report Card: Update for 2010 ─ Greeland, NOAA (19 October 2010) (paragraph split)
The research group attributed these conditions to (i) a warmer and drier winter, with a consequently reduced albedo (a measure of surface reflectivity), and (ii) a very warm and less snowy summer, again with a reduced albedo.
Less snow and ice cover, reducing albedo, means greater rock and soil warming, which increases melting still further.
The 2009-2010 result has been the highest ice melt rate since 1958, when data necessary to make the model’s calculations were first collected.