Australia’s Bureau of Meteorology (BoM) and Commonwealth Scientific and Industrial Research Organisation (CSIRO) have published the biennial State of the Climate Report, highlighting how changes to weather and climate extremes are happening at an increased pace across the country.
The report shows an increase in extreme heat events, intense heavy rainfall, longer fire seasons and sea level rise. It draws on the latest climate monitoring, science and projection information to detail Australia’s changing climate now and into the future.
Dr Jaci Brown, director of CSIRO’s Climate Science Centre, said concentrations of greenhouse gases, such as carbon dioxide, are at the highest levels seen on Earth in at least two million years. “The concentrations of greenhouse gases in the atmosphere are continuing to rise, and this is causing Australia’s climate to warm,” Brown said.
The report also documents the continuing acidification of the oceans around Australia, which have also warmed by more than one degree since 1900. “The warming of our oceans is contributing to longer and more frequent marine heatwaves, and this trend is expected to continue into the future,” she said. “We’re seeing mass coral bleaching events more often, and this year, for the first time, we’ve seen a mass coral bleaching on the Great Barrier Reef during a La Niña year.
“The rate of sea level rise varies around Australia’s coastlines, but the north and south-east have experienced the most significant increases,” added Brown.
Dr Karl Braganza, manager of climate environmental prediction services, BoM, said the report projected increases in air temperatures, more heat extremes and fewer cold extremes in coming decades. “Australia’s climate has warmed on average by 1.47°C since 1910,” he said.
“We’ve seen contrasting rainfall trends across the north and the south of the country. There’s been an overall decline in rainfall between April and October across southern Australia in recent decades, but in northern Australia, rainfall has increased across the region since the 1970s.”
During La Niña events in 2021-22, eastern Australia experienced one of its most significant flood periods ever observed. The report shows heavy rainfall events are becoming more intense and the number of short-duration heavy rainfall events is expected to increase in the future.
Braganza said the length of fire seasons has increased across the country in recent decades. “We’re expecting to see longer fire seasons in the future for the south and east, and an increase in the number of dangerous fire weather days,” he said.
To view the State of the Climate 2022 report, published on the CSIRO and Bureau of Meteorology websites, click here.