by Catriona Nguyen-Robertson MRSV

This article follows a presentation to the Royal Society of Victoria on 12 of December, 2019 titled “Climate Extremes: Present and Future” by the 2019 Research Medallist, Professor Andrew Pitman, Director of the ARC Centre of Excellence for Climate Extremes based at UNSW.

It is all very well to present facts.

It is a fact that levels of greenhouse gases are increasing in the atmosphere. It is also a fact that we are experiencing global patterns of accelerated warming.

Professor Andrew Pitman, Director of the Australian Research Council (ARC) Centre of Excellence for Climate Extremes, presented the Royal Society of Victoria with many alarming facts. As the recipient of the RSV Research Medal in its 60^th year, he delivered a seminar explaining why we should care about the facts of climate science.

Since our earliest records, an extra 2 Watts has been added to Earth’s energy balance per square metre. According to the laws of physics, this energy has to do work – and so it does: it heats our planet. The global average temperature has increased by 1.1०C.  We are losing 127 gigatonnes of Antarctic ice per year while sea levels rise 3.3 mm per year. These changes are directly attributable to greater carbon dioxide levels. But what does this mean for us and our everyday lives?

Heatwaves are becoming longer, hotter, and more frequent. Professor Pitman recalled the heatwave of January 2009, when it reached 47०C, leading to over 200 premature deaths, buckling train lines, and a loss of approximately $800 billion. We are also in the midst of a national bushfire crisis, severely affecting multiple communities, Australian biodiversity, air quality, the loss of homes and life, and calling on a massive number of volunteers to aid however they can.

It does not help that Australia has experienced a drying trend. “Drought is becoming the default position,” says Professor Pitman. And whatever rain we have left has intensified into short, extreme rainfall events. This affects the agricultural industry, bushfire season, and our personal lives as we avoid floods and hail.

Professor Pitman is concerned that climate scientists are underestimating how quickly situations can change. Current climate models cannot capture the persistence of drought and length of heatwaves, and they struggle to simulate future rainfall extremes, sometimes because they offer conflicting results.

Climate prediction and greenhouse gas emission models are not just in the hands of climate scientists. They have to take the human population into account – demography, economics, technology, and our actions. The modelling of future carbon dioxide emissions provides multiple possible futures depending on these. Professor Pitman asks “what do you want for your future? Which do you think we can achieve?”

Global warming is not merely a problem of the environmental sciences. Social scientists, business leaders and economists have to consider how our society will influence our future, and how the environment will influence our society. For example, studies have revealed a correlation between rising temperatures and reduced work productivity in Oceania (and increased productivity in Europe).

Professor Pitman is not interested so much in what the global temperature will be, but rather in determining how this will be expressed in weather and temperatures that we feel. Will our roads become liquefied due to heat? Will we have drought or floods? Will our houses be hit by large hail stones?

Led by Professor Pitman, the ARC Centre of Excellence for Climate Extremes uses its researchers, data, modelling, and collaboration to advance Australia’s capacity to predict climate extremes and minimise the risks of extreme weather phenomenon to our environment, society and economy.

Professor Todd Lane and Dr Claire Vincent at the University of Melbourne study atmospheric processes. They have developed high-resolution cloud and weather prediction models to determine the processes controlling rainfall extremes and better predict them.

Professor Andy Hogg and Dr Andrew Kiss at the Australian National University, in collaboration with the Bureau of Meteorology and CSIRO, study ocean-atmosphere interactions and can simulate the intricacies of the flow of the Southern Ocean. They are close to achieving the highest resolution in the world for ocean-climate system models.

Climate science needs computation, data scientists, scientists and technical people to work together. Currently the best computing power is only a tenth of what is needed. Professor Pitman encourages interdisciplinary science moving into the future, so that we can best prepare ourselves with the best climate prediction models.

Climate change affects everyone and is a battle we need to fight together. Professor Pitman was presented the RSV Research Medal for his outstanding leadership, research, and innovative thinking by Dr Gillian Sparkes MRSV, Victoria’s Commissioner for Environmental Sustainability. Climate change is not just a science problem, which is why he calls for leaders in all fields to come into the conversation too. The more we know about the future, the better prepared we will be, and perhaps we can even change it.