In the recent 20 years, the ice sheets in the Greenland have been losing mass, and it continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover is still decreasing in extent.
According to the IPCC report, the annual mean Arctic sea ice extent decreased from 1979 to 2012 in the range 3.5 to 4.1% per decade, and very likely in the range 9, 4 to 13.6%per decade for the summer sea ice minimum. The Arctic sea ice has been decadal decrease most rapid in summer; the spatial extent has decreased all the time since 1979. There is a medium confidence from reconstructions that over the past three decades, Arctic summer sea ice retreat was unprecedented and sea surface temperatures were anomalously high in at least the last 1450 years.
The data also shows that Northern Hemisphere snow cover extent decreased 1.6 [0.8 to 2.4] % per decade for March and April, and 11.7 [8.8 to 14.6] % per decade for June, over the 1967 to 2012 period. The reduction in the average thickness of sea ice and changes in the features of the Arctic ice cover is correspond with warming of surface temperatures. And it is estimated that by the 2050s, there will be almost no summer sea ice in the Arctic Ocean.( Kaiser, Michel J, 2005)