Climate is defined as the mean and variation of weather over long periods of time (typically, 30 years). I emphasize the “and variation” part because climate change doesn’t just refer to a changes in the mean, it also refers to changes in the variation.
One aspect of that change in variation is highlighted in a new paper (Seneviratne et al. 2014, Nature Climate Change, 4, 161-163) which points out that although global average temperature may have been increasing more slowly recently than in the previous two decades or so, the frequency of hot days in land areas has been increasing faster recently than in the previous two decades or so.
Open Mind 