Can public perceptions of Australian climate extremes be reconciled with the statistics of climate change?

Abstract

In this study alternative understandings of extreme climate events are examined by focusing on the consecutive spring record-breaking temperatures observed in Australia in 2013 and 2014. Aspects of these extremes have previously been investigated scientifically. However, widely held popular perceptions, such as those epitomised by the public statements of recent Australian Prime Minister Tony Abbott, refute the outcomes of these scientific analyses. Instead, these posit that new temperature records are purely an artefact of natural variability and the longer the period of observations available, the greater possibility of extreme events. Here, I characterise these understandings as alternative mental models of climate change and extremes, with one informed primarily by personal perceptions (The Natural Variability Concept), and the other (The Probabilistic Change Concept) informed by evidence of the physical climate system (i.e., high-quality observed temperatures and a suite of Coupled Model Intercomparison Project phase 5 (CMIP5) climate models). Using these tools, I demonstrate that observed temperature characteristics are irreconcilable with the personal perception-based understanding of extremes as artefacts only of natural climate variability. In addition to showing that the perception-based understanding of climate change and extremes adopted by Abbott (i.e., the Natural Variability Concept) is not fully consistent with the observed time series, I also show that it cannot be internally consistent. The use of these commonly employed statistical properties of temperature time series to examine directly elements of the perception-based conceptualisation of extremes provides insight into the communication of the scientific basis of extreme climate events. I suggest that further quantitative attribution statements are unlikely to explain such extremes more fully than information already available to the public. Directly addressing the misplaced foundational beliefs of the Natural Variability Concept, however, may help accurately communicate aspects of climate extremes more clearly to those open to learning from personal experiences.