Australian climate extremes at 1.5 °C and 2 °C of global warming

To avoid more severe impacts from climate change, there is international agreement to strive to limit warming to below 1.5 degrees C. However, there is a lack of literature assessing climate change at 1.5 degrees C and the potential benefits in terms of reduced frequency of extreme events(1-3). Here, we demonstrate that existing model simulations provide a basis for rapid and rigorous analysis of the effects of different levels ofwarming on large-scale climate extremes, using Australia as a case study. We showthat limitingwarming to 1.5 degrees C, relative to 2 degrees C, would perceptibly reduce the frequency of extreme heat events in Australia. The Australian continent experiences a variety of high-impact climate extremes that result in loss of life, and economic and environmental damage. Events similar to the record-hot summer of 2012-2013 and warm seas associated with bleaching of the Great Barrier Reef in 2016 would be substantially less likely, by about 25% in both cases, ifwarming is kept to lower levels. The benefits of limiting warming on hydrometeorological extremes are less clear. This study provides a framework for analysing climate extremes at 1.5 degrees C global warming.