Monthly sea ice data show trends of increasing sea ice extent that are slightly above the mean year - to - year variability over the satellite record (1979 to present). (nsidc.org)
In addition, year - to - year variability increased at some locations because of greater yield reductions in warmer years and lesser reductions in cooler years. (sciencedaily.com)
These shifts taken individually and together account for the year - to - year variability seen in the global average temperatures. (wxshift.com)