Science Source

Perception of climate change

States that “climate dice,” describing the chance of unusually warm or cool seasons, have become more and more “loaded” in the past 30 y, coincident with rapid global warming
Finds the distribution of seasonal mean temperature anomalies has shifted toward higher temperatures and the range of anomalies has increased
Finds an important change is the emergence of a category of summertime extremely hot outliers, more than three standard deviations (3σ) warmer than the climatology of the 1951–1980 base period
Holds that this hot extreme, which covered much less than 1% of Earth’s surface during the base period, now typically covers about 10% of the land area
Says 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
Discusses the practical implications of this substantial, growing, climate change