1. Projected changes to extremely hot and extremely dry years in Australia Penny Whetton, CAWCR, Australia
Percentage area experiencing an exceptionally hot or dry year: Southwest Western Australia
Background
The Australian Government is undertaking a Review of Drought Policy and asked CSIRO and the Bureau of Meteorology to prepare “An assessment of the impact of climate change on the nature and frequency of exceptional climatic events”.
Recent observed trends and projected changes to temperature, precipitation and soil moisture were examined in terms of the historical 1 in 25 year event
Seven regions were considered
Results
The areal extent and frequency of exceptionally hot years have been increasing over recent decades. Observed trends in exceptional dry years are less clear.
Based on 13 simulations from the CMIP3 database over the period , years currently considered exceptionally hot are projected to occur every one to two years
Years currently considered exceptionally dry are projected to occur over larger areas more often in the SW, SW WA and Vic& Tas regions, with little change in the other regions
Policy relevance
This study indicated that the existing 1 in year trigger for exceptional circumstances drought support to farmers is not appropriate under a changing climate
hot
dry
Observations
Multi model means
10-90th %-ile range