Rambling down dirt tracks towards the heart of the marshes, we spy a mob of kangaroos disappearing into dead reed beds.
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Emus dart between saltbushes running rampant over the floodplain.
The river red gums that flowered over the Macquarie Marshes, in the state's north-west, are now bare and ghostly white.
"It's a dead forest," says Katharine Catelotti, from the UNSW Centre for Ecosystem Science.
Nothing here is as it should be. The network of channels and lagoons in the Murray-Darling Basin is being snaffled by inland scrub.
Here, at Australia's most important site for mass breeding of waterbirds, I hear the cry of woodland currawongs and ravens.
"The wetland is shrinking," says Catelotti, looking at broken branches in the dry earth.
"Things were looking pretty bleak for this system already and it's going to look even worse with climate change."
The plight of the marshes is highlighted in a report that finds failures to adapt to climate change may result in catastrophic losses in areas such as the Great Barrier Reef and the Alpine region and Coorong wetlands, at the mouth of the Murray River.
The study found the 200,000-hectare Macquarie Marshes, officially recognised as a wetland of international importance, may run dry for long spells, flooding less often and with less intensity. The complex ecosystem is reliant on regular flooding and already struggling.
Dr Gilad Bino, a UNSW research fellow, stands among fallen trees and black roly-polys near the centre of the marshes. When this patch of land last flooded, in 2009-10, scientists waded about in water to their knees.
"You should be seeing live river red gums, you should be seeing lignum [wetland scrub], you should be seeing reed beds supporting waterbirds and fish spawning and micro-invertebrates," he says.
"You need a healthy system to be able to cope but the system is already degraded and under climate change we are expecting this degradation to continue."
Temperatures here will climb 2.5 degrees by 2070, while the number of heatwave days will more than double each year, according to the Climate Change Research Centre.
Government water buybacks have not remedied the toll of decades of river regulation and irrigation. Waterbird stocks have plummeted more than 80 per cent since 1983, Dr Bino says.
There are fears for the future of some endangered species, such as the Australasian bittern.
Future flooding is expected to occur less often, with less intensity and across a smaller area, Dr Bino says.
"The wetland is just one piece of an entire system in the Murray-Darling Basin and what goes on here will impact everything downstream."
We spy a pair of black swans in a small pool, near some cattle grazing in a green paddock.
The climate change report found farming productivity had already suffered due to long dry spells.
Fourth-generation cattle farmer Garry Hall, 48, is running 200 fewer breeding cows this year to cope with the dry. Even when it does flood nothing stays wet for long, he says, like water running off a dry sponge.
He's lived here his whole life, about 230 kilometres north-west of Dubbo, on wetlands so great that early explorers thought they'd discovered an inland sea.
"I could throw a stone from my garden fence to healthy marshes as a child," he says.
"It was wet the majority of the time. Now the marshes are dry most of the time, with the occasional wetting. It has changed here in every way."
