There’s a powerful moment in the recent Four Corners episode ‘Black summer ^[1]’ in which a police car, driving through a Sunshine Coast town that is engulfed in flames, receives a call to rescue a 93-year-old man. The car is already full of evacuees, but from off camera one of them says to the driver, ‘Mate, you put him in, I’ll get out.’

Those simple words of self-sacrifice are deeply moving and I’m sure not unique in this summer of disasters that has wrought so much destruction and overwhelmed our capacity to respond. With climate change magnifying bushfires and other hazards, that lone patrol car—with its dedicated professionals, underequipped in overwhelming conditions, presented with a grim choice of who survives—increasingly looks like a metaphor for our future.

In his National Press Club address last month, Scott Morrison outlined ^[2] his government’s plan to prevent this bleak prospect by strengthening Australia’s resilience to natural disasters. For the first time, the prime minister characterised the hazards arising from climate change as a national security challenge. He noted that meeting the challenge will require us to build ‘our ability to resist, absorb, accommodate, recover and transform’ from disasters, including ‘the effects of longer, hotter, drier summers’.

He is right to say we need to ‘transform’. We won’t keep pace with climate impacts by evolving or acting incrementally because they’re increasing non-linearly.

Extreme sea level events that have been historically rare (occurring once per century), in just a few decades are likely to occur annually ^[3] in many places. Extreme heat events have increased 20-fold ^[4] globally in the past three decades compared with the preceding three. The Queensland government is anticipating ^[5] that the state will soon have to endure heatwaves for 15% of the year (up from 3% today), and that these events will be hotter and last on average 30 days, rather than the current four days.

The Australian Department of Agriculture estimates ^[6] that changes in the climate since 2000 have already reduced average annual broadacre farm profits by over 20% ($18,600 per farm) and by 35% for cropping sector farms ($70,900 per farm). This equates to an average loss in revenue for the broadacre cropping industry of around $1.1 billion a year, during a period when the overall level of warming has been only about 1°C. We are on track for at least 3°C ^[7] of warming.

But the real worry is that it’s beginning to appear as though the interactions between climate hazards and their cascading impacts are a far bigger threat ^[8] than we realised. They may ultimately be more severe ^[9] than the immediate impacts.

We’ve seen recent indications of that in this summer’s bushfires, where an unprecedented drought combined with record temperatures directly contributed to the destruction of more than 11 million hectares, with cascading impacts such as hazardous air quality affecting millions of Australians; a 75% increase ^[10] in Australia’s annual emissions of greenhouse gases; at least a $4.5 billion blow ^[11] to Australia’s tourism industry; and severe losses of wildlife and biodiversity ^[12]. Things could have been worse. At one point, for example, fires threatened ^[13] the area around Warragamba Dam, which supplies about 80% of Sydney’s water.

We witnessed these cascading impacts in Queensland beginning in late 2018. Bushfires, exacerbated by drought and record-setting extreme temperatures, destroyed a million hectares of bush and farmland—the largest ^[14] expanse of Queensland affected by fire since recordkeeping began. This was followed by Tropical Cyclone Owen, which set an Australian record ^[15] in dumping 681 millimetres of rain in just 24 hours—more than Melbourne usually receives in a year. It didn’t, however, diminish the drought gripping much of the state. A few weeks later, record-setting rains flooded ^[16] more than 13 million hectares of northwest Queensland, killing hundreds of thousands of drought-stressed cattle.

And we saw it in Tasmania’s summer of 2015–16 ^[9], in which multiple extreme climate events, including the driest season and warmest summer on record and an intense marine heatwave, contributed to severe bushfires, disrupted agriculture and hydropower generation, and caused disease outbreaks in the farmed shellfish industry. These and other related effects reduced Tasmania’s anticipated gross state product by almost 50%.

Our most hazard-prone state is Queensland. It’s a harbinger of what lies ahead for all Australia in a warming climate. Remarkably, since 2017 over half of the state’s 77 local government areas have experienced three or more disasters requiring emergency financial support from the federal and state levels. These local governments are now in the unsustainable situation of chronically recovering from disasters.

Nothing but a transformation in Australia’s disaster resilience will prepare us for the increasing scale and frequency of climate hazards and the wide-ranging impact they will have on society. This transformation should start with land-use planning, which is the most important ^[17] mitigation measure for preventing future disaster losses in areas of new development. We need to increase our understanding of how climate change is expanding areas of extreme hazard and we need to take the politically difficult decision not to build in these areas.

Our existing housing and other infrastructure is already highly exposed. For example, over 10% of our GDP ^[18] and 2.2 million Australians are in places with high and extreme risk of bushfire. Properties in these areas that are destroyed by fires or other hazards will need to be rebuilt in safer places or built back better to withstand future hazards.

These steps need to be matched with greater transparency of risk information across all levels of society. Generally, information about bushfire, flood or cyclone risk is not readily available to individuals purchasing homes or businesses making investment decisions. This is a market failure that will increasingly put Australian communities at risk. The disclosure of disaster risk information should be required upon the sale or lease of property and legislation should be enacted giving homeowners the right to know about their property’s exposure to hazards.

These measures should be incorporated in the prime minister’s proposal ^[2] to establish an enhanced national accountability framework for disaster risk management with ‘targets, key actions, enhanced national standards and greater transparency’.

Incorporating them would also reinforce similar efforts ^[19] by financial regulators to ensure that firms and financial institutions understand and transparently disclose their climate-related financial risks to investors, lenders, insurers and other stakeholders. This disclosure, which is currently voluntary, ultimately will become mandatory. As it does it will trigger ^[20] enormous investments in assets that are resilient to climate and disaster risk.

If the climate warms beyond 2°C, as now seems increasingly likely, even the most ambitious transformation in Australia’s disaster resilience will be inadequate to meet the scale of the hazards and their cascading impacts. Reducing greenhouse gases globally as rapidly as possible is the single most important disaster risk treatment.

In this respect, it is encouraging that more than 80 countries have now committed to net zero carbon emissions by 2050. It was earlier reported ^[21] that the Morrison government was considering signing up to the pledge, but this week the prime minister appeared to reject ^[22] the possibility. The recent bushfire catastrophe suggests that all countries, including Australia, urgently need to lift their ambition to cut greenhouse gases.