Australia’s climate whiplash: what we know, and what we don’t
While floodwaters rise in the east and drought grips the west, Australia finds itself caught in a troubling paradox. The role of climate change is undeniable — but its influence is complex, and the full picture is still coming into focus.
NSW is currently experiencing unprecedented flooding. Last week, the Bureau of Meteorology gauge at Taree airport recorded 491 millimetres of rain in 72 hours. Up to 10,000 properties have been affected, and five people have died.
“The shocking current flood event in the Hunter River Basin, NSW, provides compelling evidence of the growing influence of climate change on regional rainfall patterns,” says Dr Mahdi Sedighkia, an expert in flood modelling and assessment from The Australian National University. “We are clearly witnessing a marked increase in both the intensity and frequency of extreme weather events, highlighting the urgent need to reassess how we understand and manage flood risks.”
Meanwhile, vast areas of South Australia, Western Victoria, Tasmania and much of Western Australia are locked in drought.
How climate change fuels extremes
The complexity of extreme rainfall and drought makes it difficult to distinguish the role of climate change from natural variability — that is, standard, or ‘natural’ weather fluctuations. However, we do know that climate change disrupts the water cycle, which contributes to extreme weather events.
Normally, when the Sun’s energy reaches the Earth’s atmosphere, some of it is reflected back into space, but some is absorbed by the land and the oceans, heating the Earth. The polar ice caps also reflect some back to space.
This natural process helps keep the planet warm enough to support life. However, human activities — especially the burning of fossil fuels like coal, oil, and gas — are releasing large amounts of greenhouse gases into the atmosphere, disrupting this natural balance. These gases — including carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) — trap additional heat, effectively creating a ‘blanket’ around the Earth and causing the planet’s temperature to rise over time.
Australia has warmed, on average, by 1.51 °C since national records began in 1910, with most warming occurring since 1950.
As the atmosphere warms, the patterns and amounts of rainfall change, and in some regions, this causes an increase in droughts. A warmer atmosphere is “thirstier”, which leads to more water evaporating from the soil, plants, and oceans. This can dry out the land faster, making droughts more intense and frequent, especially in areas where soil moisture is already limited, like inland Australia.
At hotter temperatures, water molecules are more likely to go into the vapour phase, increasing the amount of water vapour in the air. The amount of water vapour in the atmosphere reached a record value in 2024, at about 5% above the 1991–2020 average. So, when it does rain, heavier downpours and flash flooding are more likely.
No simple answers
But exactly how climate change translates into extreme weather events—and how far its reach extends—remains a deeply complex question.
Earlier this year, Australian researchers published a major paper examining the factors behind the record-breaking flooding and rainfall that struck Eastern Australia in 2022. They found it “reasonable to conclude” that climate played a role in the event. However, they noted that “quantifying this effect is challenging due to the complex nature of the event and the deficiencies in correctly simulating precipitation and associated processes in climate models”.
“We can partly explain these extreme rainfall events because of the warming atmosphere. We know climate change contributes, but it is not simple,” says Professor Andy Pitman, a climate scientist based in the Climate Change Research Centre at UNSW. “If you want to quantify the degree to which climate change contributed, then you either need people who will simplify things beyond what the science will accept, or you won’t get a simple answer”.
“If you eat three McDonald’s a day for five years, you can’t directly attribute your health consequences to that, but you can be pretty confident that it’s a factor”, says Pitman. “Similar to global warming, it’s a factor in these things, it’s very hard to determine the degree to which it’s a factor for extreme rainfall”.
Climate change and disasters
