In a review of the DECR report, Dr David Stockwell showed that the DECR results for rainfall were supported only by climate models that appear to have little skill in matching past rainfall patterns let alone forecasting future patterns.
Furthermore, the summary assessment in the DECR, quoted by the Department of Agriculture’s press release and amplified by the Prime Minister, misleadingly present only the lower tail (10th percentile) of the rainfall outlook developed by the CSIRO and Australian Bureau of Meteorology for their report, Climate Change in Australia. The mean results of those projections are a slight decrease in drought frequency.
The summary of Chapter 5, Section 2.2 of that report says:
“The range of precipitation change in 2030 allowing for model to model differences is large. Annually averaged, the 10th to 90th percentile range is around ‑10% to +5% in northern areas and ‑10% to little change in southern areas.” (emphasis added)
David is presenting his results in a series of posts at Niche Modeling.