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Australia’s climate is getting hotter with more extreme heat events, longer fire seasons, more intense heavy rainfall and rising sea level.
That was the finding of the State of the Climate 2024 report released by the CSIRO and Bureau of Meteorology.
Scientists found the oceans around Australia are continuing to warm with greater atmospheric carbon dioxide leading to more acidic oceans, particularly south of Australia, the report says.
CSIRO Research Manager Dr Jaci Brown says ocean warming contributed to longer and more frequent marine heatwaves; the highest average sea surface temperature on record was in 2022.
“Increases in temperature contributed to significant impacts on marine habitats, species and ecosystem health, such as the most recent mass coral bleaching event on the Great Barrier Reef this year,” she says.
“Rising sea levels around Australia are increasing the risk of inundation and damage to coastal infrastructure and communities.”
She says the global mean sea level rose by around 22 centimetres since 1900, half of it since 1970.
“The rates of sea level rise vary across the Australian region with the largest increases in the north and south-east of the Australian continent,” Dr Brown says
The amount of greenhouse gases in the atmosphere continues to increase, contributing to climate change, with 2023 the warmest year on record globally.
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Dr Karl Braganza, Climate Services Manager at the Bureau of Meteorology, said Australia is continuing to warm; eight of the nine warmest years on record occurred since 2013.
“This warming has led to an increase in extreme fire weather, and longer fire seasons across large parts of the country,” he says.
The report says a shift towards drier conditions between April to October across the southwest and southeast, and reduced rainfall in southwest Australia, now seems to be a permanent feature.
“The lower rainfall in cooler months is leading to lower average streamflow in those regions, which can impact soil moisture and water storage levels and increase the risk of drought. Droughts this century have been significantly hotter than those in the past,” Dr Braganza said.
“However, when heavy rainfall events occur, they are becoming more intense, with an increase of around 10 per cent or more in some regions.
“The largest increases are in the north of the country with seven of the 10 wettest wet seasons since 1998 occurring in northern Australia.”
Although emissions declined since 2005, Australia is expected to experience continual warming over coming decades with more very hot days and fewer very cool days.
The report is the eighth in a series published every two years by CSIRO and the Bureau of Meteorology. It draws on the latest national and international climate research, monitoring, and projection information to describe changes and long-term trends in Australia’s climate. The 2024 report can be found on the CSIRO and Bureau of Meteorology websites.
