Public Perception of Climate Change and the New Climate Dice

TL;DR

This paper discusses how climate dice have become increasingly loaded due to global warming, leading to more frequent and extreme hot seasons, with significant implications for understanding and communicating climate change impacts.

Contribution

It introduces the concept of 'loaded' climate dice, quantifies the increase in extreme hot anomalies, and links these changes to global warming with high confidence.

Findings

Extreme hot anomalies now cover about 10% of land area

Likelihood of recent extreme events without global warming is exceedingly small

Distribution of seasonal temperatures has shifted toward higher anomalies

Abstract

"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.