On 14 November the Age published a short letter from Tom Beer, retired CSIRO scientist, on the bushfire emergency of our northern neighbours. Beer looked up an article he had lead authored in 1987 the conclusion of which was that with climate change “the fire danger every year on average would be larger than the fire danger during the year (1983) in which Ash Wednesday occurred.” This was followed up immediately by Graham Readfearn in a great article that expanded on Beer’s work in the CSIRO department of atmospheric physics and looked at the effort of others including Graeme Pearman and Barrie Pittock. Readfearn noted that the science had not changed since 1987 – referring to the Monash Conference when over 50 papers including Beer’s were presented.
He continued: “What Pearman is seeing play out now, in the bushfire crisis and the drought, “is what we were talking about at the Greenhouse 87 meeting. That was about the changes that we anticipated, based on basic physics of the climate system.” Despite the fact that Pearman gave more than 500 presentations on climate change between 2000 and 2010, he still asks himself if he could have done more. “What could I have done? What did I do wrong?”
Interestingly one set of data used by Beer et al* was from East Sale Air Base from 1945-1986. The abstract of the paper noted the importance of humidity and that “estimating the likely changes in relative humidity for any future climate scenario is vital for examination of future bushfire incidence” with relative humidity being a function of a number of factors including temperature rainfall and wind.
For those too young to remember on Ash Wednesday 16 February 1983 over 100 fires burned across Victoria and South Australia causing 75 fatalities and the loss of over 2,500 homes. It was an El Nino year and very dry when many of the rivers in East Gippsland stopped flowing. This century has started to fulfil the forecasts of Tom Beer. Both the 2003 and 2006/7 fires in Gippsland burned huge areas for more than 2 months. The fatalities and damage caused by Black Saturday have eclipsed all previous bushfires. The NSW and Queensland fires look set to burn for some time yet. And summer is yet to come**.
*T.Beer, A.M. Gill and P.H.R.Moore “Australian bushfire danger under changing climatic regimes” p.421 in G.I.Pearman (ed.) Greenhouse: planning for climate change, CSIRO Australia, 1988
**Since this was written a number of ‘unprecedented’ bushfires have been burning in Gippsland at Gelantipy, Ensay, Bruthen and other locations.