Australia has experienced a season of extremes last summer, with the Australian Actuaries Climate Index posting a record-number of hot days, extreme rainfall in tropical regions, as well as ongoing drought in some parts of NSW.
The climate index showed a 200% rise in the frequency of extreme high temperatures in the summer of 2018-19 compared to the reference period 1980-2010.
“The most recent summer has been the hottest on record, both in terms of average temperatures as reported by the Bureau of Meteorology, and in terms of the frequency of extreme temperatures as measured by the Australian Actuaries Climate Index,” said Tim Andrews, who led the development of the index. “The Bureau of Meteorology predicted this summer’s hot weather and reported it would be driven by a combination of the long-term increasing trend in global air and ocean temperatures, and the El Niño weather conditions.”
The climate index also showed clear evidence of the sustained rainfall that caused the 1-in-100-year flooding in North Queensland in February, as well as the continuing drought experienced in central NSW.
“The attribution of individual events to climate change is challenging to assess due to high levels of natural variability, but the Townsville event is consistent with expectations for rainfall intensity to increase,” Andrews said.
Andrews also noted that despite the heavy rainfall in north Australia, there were significant parts of NSW and Southern Queensland experiencing extremely dry conditions during the summer months.
The climate index, launched last year, tracks changes in the frequency of extreme high and low temperatures, heavy precipitation, dry days, strong wind, and changes in sea levels, to help businesses better assess how weather extremes translate into financial risk.
