The summer of 2021/22 in Australia continued the trend set by a wet spring, with ongoing La Niña resulting in increased rainfall and warm ocean temperatures on the country’s east coast, according to the Actuaries Institute’s latest Climate Index.
Launched in November 2018, the Actuaries Institute Climate Index is an objective measure of extreme weather conditions and sea level changes.
The latest index said La Niña has been in effect since November 2021, which played a part in the higher rainfall in the eastern parts of the country and may lead to a continuation of wet weather in autumn.
The Bureau of Meteorology made similar observations on rainfall this summer, noting that it was above average along the east coast and in parts of South Australia (SA), but below average in southern Western Australia (WA) and Tasmania.
Regarding sea-level changes, the Actuaries Institute Climate Index revealed that sea surface temperatures had been unusually warm off Australia’s east coast, contributing to higher sea levels as the warmer water expands.
Meanwhile, the Murray Basin – covering parts of New South Wales (NSW), Victoria, and SA – set a record for the extremely low temperature index this summer. This trend was also seen in the Southern Slopes Victoria, which has not had a negative minimum temperature index value since 2012.
“Trends of this nature can impact the propagation of diseases, pests, and insects that were previously less likely to survive in lower temperatures,” the index warned.
The climate index also shared information about the catastrophic flooding in Queensland and NSW in late February this year, reporting 22 deaths and around $2.5 billion of insurance claims as of April 14, 2022. However, despite what was seen on the ground, it did not have records for the east coast north and east coast south clusters for the 2021/22 summer because it only covered three months of information and large geographical areas, reflecting overall climate trends as opposed to localised catastrophes.
Commenting on the latest climate index, Actuaries Institute president Annette King said: “The Australian Actuaries Climate Index is a great example of how Actuaries use data for good, in this instance by objectively analysing complex data sets to provide easy to understand insights on an important issue.”
