We must prepare entire cities for extreme heat. Our new study reveals how

by bpckle | Oct 22, 2026 | In the Media

In Australia, the days are growing longer and summer is fast approaching. But a very strong El Niño – a natural weather phenomenon that drives variations in temperature and winds across the Pacific – could make this summer a sweltering one.

This raises the question: are we ready for extreme heat?

Our new research examined how Australia’s Greater Sydney region is preparing for surging temperatures and more frequent heatwaves. In particular, Western Sydney is known for its stifling temperatures, at times being the hottest place on the planet.

We found this city-wide approach involves much more than simply telling people what to do when temperatures soar.

A societal problem

Many Australians know how to cope with hot weather. We drink plenty of water, close blinds and curtains, stay indoors when the sun is at its strongest and regularly check on family, friends and neighbours.

This is good advice. However, not everyone can act on it.

For some people, staying cool is much easier said than done. Not everyone can afford to keep the air conditioner running. Not everyone has a well-insulated home, particularly those living in older homes. Not everyone is well-connected to their neighbours and wider community.

This raises several crucial questions:

• how can we protect those most vulnerable to extreme heat, including the elderly, pregnant women and people with existing health conditions?

• how should we design houses, streets and neighbourhoods to reduce heat exposure in the first place?

• where else can residents go if they need relief from soaring temperatures?

Read more: Europe is battling a record-breaking heatwave. What’s making it so severe?

Preparing a city for heat

Our latest research took a closer look at how one city is preparing for extreme heat.

The Greater Sydney Heat Taskforce, established in 2023 and led by the Western Sydney Regional Organisation of Councils and Resilient Sydney, aims to help nearly 5.6 million Sydneysiders cope with rising temperatures.

This taskforce brought together 373 representatives from more than 40 organisations across government, health, emergency services and other sectors. Over an 18-month period, these representatives developed the Greater Sydney Heat Smart City Plan. The plan was launched in December 2024 and is now being implemented.

The plan sets out 40 recommendations for action between 2025 and 2030. These cover topics such as raising awareness about heat-related risks, designing cooler homes and neighbourhoods and protecting vulnerable communities.

The plan also underscores the need for better coordination of services and emergency responses. Unlike floods and bushfires, which trigger specific, established emergency actions, extreme heat has historically fallen between different areas of government.

As researchers working within the taskforce, we examined how the Heat Smart City Plan helped bridge these gaps and identified ways to turn its recommendations into action.

Here are our three main findings.

Coordination is key

To create an effective plan, the Greater Sydney Heat Taskforce had to overcome organisations working in silos. For example, health agencies focus on heat-related illness, while councils manage how public spaces and planning authorities shape the built environment. This means responses to heat risk are often fragmented. By contrast, the Heat Smart City Plan helped organisations build trust, clarify responsibilities and identify gaps in governance.

Communities must be involved

By engaging community groups, including Sweltering Cities and the Western Sydney Community Forum, the taskforce built community experiences into the plan. This boosted support for initiatives like Extreme Heat Awareness Day.

Collaboration alone isn’t enough

Long-term funding, clear responsibilities and ongoing support from local institutions are key to the success of any city-wide heat plan. The Heat Smart City Plan identifies the lead organisation responsible for turning recommendations into action. We found this encouraged organisations to take ownership and incorporate heat preparedness into existing planning, emergency management and climate adaptation frameworks.

The NSW government, for instance, is exploring how urban greening, improved shade and heat-sensitive building design can be incorporated into planning through its draft State Environmental Planning Policy.

Read more: A solution to cut extreme heat by up to 6 degrees is in our own backyards

More work needed

The Greater Sydney Heat Smart City Plan is a step forward, but the challenge now is turning its ambitions into practical, lasting changes across government and industry.

Promising initiatives already exist. The Australian Red Cross’s TeleRedi program, currently run in South Australia and Western Australia, sees volunteers check in on vulnerable people during dangerous weather.

In Blacktown, libraries and other air-conditioned public facilities offer places to escape the heat, as outlined in the council’s Beat the Heat guidance.

These initiatives are not complicated or new. But making them available where needed requires long-term funding and coordination across housing, infrastructure, health and emergency services. Only then can we protect lives and communities in a warming world.

We’d like to thank Kerry Robinson (Greater Sydney Heat Taskforce Chair), Judith Bruinsma and Kelly Gee (Western Sydney Regional Organisation of Councils, WSROC) and Melinda Dewsnap (Resilient Sydney) for facilitating the taskforce, alongside all its members. We particularly recognise the late Charles Casuscelli, former CEO of WSROC, whose leadership was instrumental in driving this work forward.

Read more: Extreme heat is harming remote First Nations communities. It’s time we listen to them

Nicky Morrison received funding for this research through Project Mezze, a joint initiative of Western Sydney University and the University of New South Wales. She also receives research funding from the NSW Decarbonisation Innovation Hub, Environment Protection Authority, Department of Planning, Housing and Infrastructure, Urban Development Institute of Australia, Business NSW and local councils.

Patrick Harris receives funding from the National Health and Medical Research Council, Australian Research Council and Australian Housing and Urban Research Institute.

Vanita Yadav receives funding from the Australian government’s Centre for Australia India Relations to support her research work in agribusiness and international trade.

Why the humble rabbit might be Australia’s worst introduced species

by bpckle | Oct 21, 2026 | In the Media

The 19th century pastoralist Thomas Austin was homesick. He yearned for the pastimes of his home in England – especially rabbit hunting. He asked his family to send him some rabbits.

On Christmas Day in 1859, around two dozen wild and domestic rabbits arrived in Australia.

Delighted, Austin released them on his Barwon Park estate near Geelong. A member of the Acclimatisation Society of Victoria, Austin was among many working to bring European animal species to Australia. Of his efforts, he would later write:

the introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting

Domestic rabbits first came to Australia with the First Fleet. But these introductions were domestic rabbits and didn’t establish.

Austin’s rabbits fared differently, as they were from wild genetic stock and much better suited to establishing self-sustaining populations. These rabbits began one of the most devastating biological invasions in Australia’s history. Rabbits, after all, breed like rabbits.

Every Australian knows common myna birds are bad, rabbits are worse and feral cats kill native animals unchecked.

But how do we decide what makes an introduced species “good” or “bad” – and will we ever concede that some species are here to stay?

Our new series on invasive species explores these questions.

It didn’t take long for rabbits to go from desirable to undesirable. In the 1950s, CSIRO scientists began releasing biocontrols – viruses lethal to rabbits. Rabbit numbers are now estimated at around 200 million, vastly lower than a century ago. Even so, rabbits are resilient. They remain one of Australia’s most widespread and damaging invasive species – perhaps even the worst.

What’s the issue with rabbits?

As rabbits spread across the continent, their numbers grew to plague proportions. Farmers came to loathe them for their ability to eat through pastures, spread weeds and dig huge warrens.

Desperate farmers resorted to traps and poisons, while many people worked as rabbiters. Some farmers were forced to abandon their properties.

In 1901, West Australian authorities saw rabbits approaching and began building enormously long fences to keep them out. It was pointless. By 1920, Australia had an estimated 10 billion rabbits.

Rabbits don’t just affect farmers

As highly efficient grazers, rabbits compete for food with endangered yellow-footed and brush-tailed rock-wallabies, southern hairy-nosed wombats and many other native herbivores.

Rabbits consume up to a third of their body weight each day. Even at very low densities, they can stop regrowth of native trees and shrubs by selective grazing. Their digging of large warrens can increase erosion, degrade the surrounding land and accelerate the spread of invasive weeds.

Rabbits are incredibly good at making more rabbits. A doe can get pregnant and give birth about 30 days later to between three and eight kittens. A single doe can produce up to 50 kittens a year. Young rabbits begin breeding at around 4 months old.

Their sheer fecundity makes them hard for native or introduced predators to control. In some areas of Australia, European rabbits can breed year-round.

As a result, Australia’s rabbits threaten over 300 species of native animals and plants.

Rabbits also represent an abundant source of prey for foxes and feral cats, two introduced species which have become apex predators in Australia. These opportunistic hunters kill and eat threatened bilbies, bandicoots, lizards and birds, too. Foxes also target lambs and other young livestock, leading to major losses for farmers.

The sheer size of the rabbit population supports large numbers of cats and foxes, intensifying the damage to native species.

Biocontrols work – but are not a silver bullet

In the 1950s, scientists at CSIRO researched and then released the first biological control for rabbits, Myxoma virus. This virus causes the lethal disease myxomatosis, which slashed rabbit numbers by an estimated 95% in some areas.

Over time, the surviving rabbits built up resistance to Myxoma virus.

In 1984, another virus was identified in domestic rabbits in China. Rabbit calicivirus – otherwise known as Rabbit haemorrhagic disease virus – spread and infected rabbits in many countries.

In 1995, scientists began testing calicivirus on South Australia’s Wardang Island. It was an ideal biocontrol candidate, as it only infected rabbits, was stable in the environment and caused a disease with rapid onset and progress.

During testing, the virus was carried by flies to the mainland. In the wild, it proved highly effective at keeping rabbit numbers down, though surviving rabbits began to develop immunity.

About 20 years later, a highly virulent new strain appeared in Europe and spread to Australia, where it cut rabbit numbers by 60%.

In 2017, authorities released a new strain of the calicivirus, known as K5, to augment the effectiveness of the naturally circulating virus strains.

This year, sharp rises in rabbit numbers have been reported. We don’t yet know if this is due to a mild winter and plant growth after good rainfall, a reduction in effectiveness of the circulating viruses, or both.

So how can we get on top of this trend before the rabbits get out of hand again?

At CSIRO, we have developed a new way of growing rabbit calicivirus in the lab to speed up selection of new variants with potential to boost control.

We are also tracking virus strains circulating in Australia to map the activity of the various rabbit biocontrol viruses. Anyone can send in samples from rabbit carcasses to be tested through our citizen science project.

CSIRO researchers have begun investigating longer-term solutions such as genetic biocontrol (commonly known as gene drives) for key pests – including rabbits.

There is no single answer

While rabbit viruses work very well for a time, they are not a silver bullet.

To keep numbers down long-term, we need to combine viruses with other control methods such as baiting, fumigation and destruction of rabbit warrens and, ultimately, novel technologies such as gene drives.

If we do nothing, we will once again have a true plague of rabbits. Keeping them under control is essential.

Ina Smith works for CSIRO, which researches and releases rabbit biocontrols.

Elena Smertina works for CSIRO, which researches and releases rabbit biocontrols.