The Trump administration has dismissed the authors of its Sixth National Climate Assessment. To some this may seem like just another anonymous government report being shelved. Why should this draconian action be headline news? And why should we care about this precedent here in Australia?
Climate change is affecting us all. But while the US has completed five previous climate risk assessments, each building knowledge about the impacts of climate change on the country, here in Australia we’ve still only published part of our first National Climate Risk Assessment.
Regular climate risk assessments, ideally supported by legislation and released on a regular cycle, ensure the best available science is used to inform planning and policy. They not only help ensure that taxpayer resources are used efficiently, but can underpin both public and private-sector strategies that build greater climate resilience for our people, the environment, infrastructure, and the broader economy.
In Australia, we’re fortunate to have plenty of information on how our climate is changing.
We know that southern parts of Australia are getting drier, flooding is becoming more intense when it happens, our temperature extremes are rising fast, we’re getting more bushfire weather, we’re seeing fewer but more intense tropical cyclones, and that our seas are getting warmer, more acidic, and rising with impacts right along our coastline. There’s much we do know about the hazards.
The costs of the unknown
But what we don’t know anywhere near as well is how changes to these hazards will impact us. We simply cannot adapt to the impacts of climate change if we don’t understand them.
Without this knowledge and coordination, we run the significant risk of making rapid, costly, and possibly even wrong decisions at the last minute. Haphazard approaches run the risk of making things worse for the people who are our most vulnerable.
A national climate risk assessment is the only way we can make an evidence-based, just and equitable national climate adaptation plan.
So what exactly is a climate risk assessment?
There are the obvious and direct implications of climate change, such as experiencing heatwaves more often and personally feeling sweaty and uncomfortable, but what and who does that heatwave really impact and cost?
To calculate this, we need to understand not only the hazard, but what is exposed to that hazard and the changes in vulnerability if that hazard increases over time.
Heatwaves alone kill more people than any other natural hazard in Australia. But heatwaves also impact our ability to supply enough electricity to meet demand, they dry the landscape, making it more susceptible to fire, bend railway lines and crack roads affecting supply chains, they make some medicines less effective, shut down outdoor worksites, kill native and agricultural vegetation and animals, and may even be so intense and occur so often that some communities may simply become unliveable.
And that’s just the short version of a very long list of what is exposed to heat.
Heatwaves also greatly increase the vulnerability of certain sectors of our community – the very young and very old, the infirm, the homeless or houseless, people in remote communities, people without access to cool places or transport, Indigenous populations. The list is very long.
In essence, anyone or anything who cannot rapidly adapt or escape will suffer more.
Compounded risk for disaster
And, of course, the risk compounds with other hazards. A heatwave and a fire may occur at the same time following drought, or a heatwave may follow a tropical cyclone that has also produced flooding, or the heatwave may be so humid that even fit bodies simply cannot survive.
There are many examples from Australia and overseas where the impact from a single hazard is modest, but when multiple hazards occur together or in quick succession, the impacts compound to disastrous levels.
The first pass of Australia’s first National Climate Risk Assessment was released in March 2024. It had gathered hundreds of subject-matter experts from across the nation who identified several hundred major climate risks to Australia over the coming century. These were ultimately pared down to “just” 56 nationally significant climate risks.
This is the first time Australia has developed a holistic view of what may be at risk from climate change. This is a game-changer for Australia not only being prepared, but also started the process for being able to budget for a climate-changed future, as the costs of adaptation are typically much lower when adequately planned and accurately targeted to projected changes.
Recent concerns regarding the escalating costs of insurance clearly illustrate the importance of preparedness in the face of climate risks.
Not a set-and-forget process
So why does the shutdown of the US National Climate Assessment send a word of warning to us? Because a national climate risk assessment, being the critical evidence base for a national adaptation plan, is not a set-and-forget process, in a similar way to a national budget or even taking care of our own health must be regularly assessed and updated.
As the science and modelling of climate change becomes increasingly robust and our understanding improves of our exposure and vulnerability to changes or shocks to our weather and climate, we need to constantly reassess our risks and make adjustments to protect our people, environment, infrastructure, and economy.
The Climate Change Authority recommends that a National Climate Risk Assessment be repeated every five years in Australia to match new census data and Treasury intergenerational modelling about our society and its future makeup, as well as approximately matching global climate dataset updates.
Similar calls have come from think-tanks such as the Australian Strategic Policy Institute (APSI), the Investor Group for Climate Change and independent federal senators.
Understanding what’s at stake
Climate change isn’t going away any time soon, even if we rapidly take action to reduce global CO₂ emissions. Some impacts are already locked in for millennia.
Understanding what we risk losing, and building genuine and equitable resilience to what cannot be avoided, requires constant vigilance through ongoing global, national and local risk assessments.
Knowing what’s really at risk from climate change is critical information for developing effective adaptation strategies and safeguarding a nation’s future, whether it be Australia or the United States.
Stopping or even slowing the risk assessment process is, at best, dangerous. Mandated and regular risk assessments are needed now more than ever. The dismissal of the US climate assessment authors is a precedent no nation can afford to follow.
This article was co-authored withTas van Ommen, Australian Antarctic Program Partnership, University of Tasmania; Brenda Lin, CSIRO Environment; Sonia Bluhm, Scientell; Angela Koning, EQUENTI Leadership and Learning.
