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1 November 2021
Extreme high or low temperatures, high rainfall, strong wind or rising sea levels featured in all but one of Australia’s last 43 seasons, the Actuaries Institute says.
The Australian Actuaries Climate Index, released quarterly using data from the Bureau of Meteorology, shows that since 2011, only winter 2015 avoided weather considered to be historically extreme.
A review of data since the beginning of 2011 showed record high and low temperatures in 36 of the 43 seasons, and higher than average sea levels in 40 seasons.
“Over the last three years, we have seen record high and low temperatures and Index values that are consistently above the reference period, which is evidence of the effect of global warming on Australia’s climate,” Actuaries Institute lead researcher Rade Musulin said.
The index tracks changes in temperatures, precipitation, dry days, strong winds and sea levels across a dozen Australian regions that are climatically similar, measuring extreme weather or sea levels to show how the occurrence of extremes is changing over time.
Each season is compared to the same season in previous years, and against a reference period from 1981-2010.
The Index for winter this year, the latest quarter, set no national records but the Institute says the trend to extremes continues. Winter was one of the warmest on record, and nationally rainfall was 4% below long-term averages even as parts of Victoria experienced extreme flooding in June, with some rivers rising by up to five metres in 12 hours at the beginning of the month.
Actuaries Institute CEO Elayne Grace says it is clear that the Index is showing more extremes over time.
“It’s up to all stakeholders, including governments, business and individuals, to ensure those increased risks are mitigated and a steady transition made to a sustainable future,” she said.