Australia’s land surface has warmed by 1.5C since 1910, according to the Bureau of Meteorology’s long-term record of temperatures.
The figure is revealed in the bureau’s annual climate statement that found 2023 was Australia’s joint-eighth warmest year on record, with the national temperature 0.98C above the average between 1961 and 1990.
Countries around the world have agreed to “pursue efforts” to keep global heating to 1.5C, but this temperature goal is widely accepted as being relative to a pre-industrial period from 1850 to 1900 and combines land and ocean temperatures across the globe.
The bureau’s declaration that the continent has warmed by 1.5C has a margin of error that is plus or minus 0.23C, includes only land temperatures and does not relate to targets to keep global heating to 1.5C.
Dr Simon Grainger, a senior climatologist at the bureau, said the warming of Australia’s land surface had moved from 1.48C to the new 1.5C mark after another year of data was added.
“This warming [in Australia] is consistent with a global climate that is warming with 2023 being the warmest year on record globally,” he said.
Global heating is being caused mainly by the burning of fossil fuels and land clearing that has increased the amount of CO2 in the atmosphere by about 50% since the 18th century.
Dr Andrew King, a climate scientist at the University of Melbourne, said he was “not surprised” Australia’s land surface had hit 1.5C “because we know Australia is already warming above the global average”.
“We also know that the land is warming faster than the ocean and many regions are warming faster than the global average,” he said.
A study published last year using Australia’s official records supplemented by older temperature observations, found the land had warmed by about 1.6C relative to the period between 1850 and 1900. Australia’s land surface had warmed at about 1.4 times the global average of 1.1C, the study said.
Dr Linden Ashcroft, a climate scientist at the University of Melbourne, said: “Every hundredth of a degree of warming matters. [Hitting 1.5C] might be symbolic, but it does not make it any less scary. It’s a jolt.”
Several major cities experienced maximum temperatures that ranked in the top 10 for all years since their respective records began, the bureau said.
Sydney, with a record going back to 1858, had its equal second warmest year on record for maximum temperatures.
Canberra, Hobart, Brisbane, Perth and Darwin also experienced maximum temperatures that ranked in the top 10 for all years.
Sea surface temperatures around the continent were the seventh-warmest on record and 0.54C above the average between 1961 and 1990, the bureau said. The Australian region had seen above average sea surface temperatures every year since 1995.
Overall, Australia’s ocean waters have warmed by 1.05C since 1900 and nine of the 10 warmest years on record since 1900 have occurred since 2010, the statement said.
Australia’s climate of 2023 was bookmarked by a fading La Niña system in the Pacific Ocean at the start of the year that flipped to the generally warmer and drier El Niño phase at the end of the year.
The winter of 2023 was the warmest on record and the period of August to October was also the driest of any three-month period on record going back to 1900. September was the second driest on record for any month, behind April 1902, the statement said.
Grainger said: “We’re not just experiencing really hot days in summer. Australia had the warmest winter on record in 2023 and the warmest June to November period on record.
“Climate change isn’t just bringing extreme conditions in summer but it’s giving warm days and nights throughout the year.”
