As a climate scientist, I know heatwaves in Australia will only get worse. We need to start preparing now | Sarah Perkins-Kirkpatrick

When the forecast for this week started to come in, my mind immediately went back to Australia’s dark summer.

I had taken my daughters to the swimming pool at our estate in western Sydney, hoping for a brief respite from the unrelenting heat. The Gospers Mountain Fire was raging in the Blue Mountains, but on this day the smoke didn’t seem too intense.

We had been in the water for barely five minutes when ash started falling from the sky. The delicate black flakes rested gently on the heads of my young children, a poetic and calm omen for their future.

Six years later, southeast Australia is in the grip of another heatwave – the worst since 2019-2020. Melbourne and western Sydney will reach temperatures in the low 40s, with regional cities in Victoria and New South Wales even higher. Canberra – where I currently live – is experiencing consecutive days in the 30s.

Heatwave conditions are severe to extreme across large areas of South Australia, Victoria, New South Wales and the ACT until Saturday. From Friday, strong winds associated with a cold front will cross Victoria and New South Wales, a particularly dangerous fire pattern reminiscent of the Black Saturday fires of 2009.

Fortunately, some of the conditions that led to this heatwave are not as bad as in 2019 or 2009. The main difference is that we are not in a multi-year drought, which means the fuel has not dried up to the same extent. We also now have a National Fire Danger Index and, as a population, are generally more aware of how to prepare for imminent fire danger.

Perhaps, hopefully, these factors will be enough to prevent a devastating fire like those that followed previous severe heatwaves, despite large fires already burning in Victoria. But we must not rest on our laurels.

We cannot talk about such an extreme heatwave without mentioning its impacts on health. I want to be very clear here: extreme heat kills. In fact, extreme heat kills more Australians than all other natural hazards combined.

We have been lucky not to have experienced such a severe heatwave for over five years. While the triple La Niña episodes helped cause disasters of a different kind, they also silenced, at least temporarily, the growing urge for extreme heat. The precipitation they brought recharged moisture levels on the land surface, breaking the inextricable link between drought and extreme heat. However, recent drier than normal conditions in the Southeast have allowed this link to begin to re-form, although not (yet) with the same intensity as the Black Summer.

And then there’s the elephant in the room we wish we could ignore: climate change.

The link between heat waves and climate change is very clear: as the global average temperature increases, the frequency, duration and intensity of heat waves also increase, even if the global average temperature increases by only 1 or 2 °C. This is not just the case in Australia, but virtually everywhere else on the planet. When it comes to how climate change drives extreme weather events, the physical link between global average temperature and heat waves is among the best studied and understood in the world.

Bottom line: We know that climate change is causing heat waves, and we know we’ll see more of them in the future. And while it’s too early to know the explicit influence of climate change on this particular heat wave, I think it will be very significant.

Reaching net zero emissions – when possible – would offer some hope. By stabilizing atmospheric greenhouse gases from anthropogenic sources, the global average temperature could stabilize. However, the real benefits are unlikely to be felt for at least 100 to 200 years. Recent research has indicated that heatwaves in Australia will continue to intensify – albeit more slowly – for at least 1,000 years, and that delaying carbon neutrality by just 5 to 10 years will result in much worse heatwave regimes for centuries to come.

We have now reached a critical point where, although imperative, net zero is no longer enough. You also have to adapt.

Effective and permanent adaptation goes hand in hand with carbon neutrality and must be the subject of legislation. Public awareness and education are also important. And it is essential that we significantly increase investments in public health, because many people will need lifesaving care during heatwaves in the decades to come.

Once again, I find myself thinking about our brief time in the pool during the dark summer. My daughters had no idea what was going on around them, and in that moment, I was grateful. But as they grow up, they become more and more aware of the world they inherit. I am careful not to weigh them down, but questions are being asked more and more about drought, fires, heatwaves and climate change.

They deserve answers. And if they and their peers want to face future heatwaves head-on, we must do better.