Australia’s weather has intensified over the past two years with an increase in extreme heat events, longer fire seasons, more heavy rainfall and sea level rise.
The latest biennial State of the Climate Report, released today by the CSIRO and the Bureau of Meteorology draws on national and international climate research, monitoring, and projection information to describe changes and long-term trends in Australia’s climate.
CSIRO Research Manager Jaci Brown said scientists found the oceans around Australia were continuing to warm, with increases in carbon dioxide in the atmosphere leading to more acidic oceans, particularly south of Australia.
Dr Brown said warming of the ocean had contributed to longer and more frequent marine heatwaves, with the highest average sea surface temperature on record occurring in 2022.
“Increases in temperature have 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 said.
“Rising sea levels around Australia are increasing the risk of inundation and damage to coastal infrastructure and communities.”
Dr Brown said global mean sea level was increasing, having risen by around 22cm since 1900, with half the rise occurring 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.”
She said the amount of greenhouse gases in the atmosphere continued to increase, contributing to climate change, with 2023 the warmest year on record globally.
Bureau of Meteorology Climate Services Manager Karl Braganza said Australia was continuing to warm, with eight of the nine warmest years on record occurring since 2013.
“This warming has led to an increase in extreme fire weather, and longer fire seasons across large parts of the country,” Dr Braganza said.
He said the report showed a shift toward drier conditions between April to October across the southwest and southeast, with reduced rainfall in southwest Australia now seeming to be a permanent feature of the climate.
“The lower rainfall in the 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 percent or more in some regions.”
He said the largest increases were in the north of the country, with 7 of the 10 wettest wet seasons since 1998 occurring in northern Australia.
Dr Braganza said although Australian emissions had declined since 2005, Australia was projected to see continued warming over the coming decades, with more extremely hot days and fewer extremely cool days.
“The rate of emissions decline will need to accelerate from now to meet Australia’s 2030 emissions targets,” he said.
Read the full State of the Climate Report 2024.
