  "Climate dice", describing the chance of unusually warm or cool seasons
relative to climatology, have become progressively "loaded" in the past 30
years, coincident with rapid global warming. The distribution of seasonal mean
temperature anomalies has shifted toward higher temperatures and the range of
anomalies has increased. An important change is the emergence of a category of
summertime extremely hot outliers, more than three standard deviations
(3{\sigma}) warmer than climatology. This hot extreme, which covered much less
than 1% of Earth's surface in the period of climatology, now typically covers
about 10% of the land area. It follows that we can state, with a high degree of
confidence, that extreme anomalies such as those in Texas and Oklahoma in 2011
and Moscow in 2010 were a consequence of global warming, because their
likelihood in the absence of global warming was exceedingly small. We discuss
practical implications of this substantial, growing, climate change.
