The government’s announcement ^[1] of a climate security risk assessment has been widely welcomed. Importantly, the timing of the risk assessment overlaps with the defence strategic review ^[2] also announced by the new government. Advice has already ^[3] been forthcoming ^[4] about how the government might best execute the climate risk assessment. What’s also needed is clear thinking on how the risk assessment and the defence review can be made to work together.

Australia’s near region is exceptionally exposed ^[5] to climate-change impacts. For example, Indonesia is experiencing some of the fastest sea-level rise in the world, is highly exposed to non-climate disaster risks like earthquakes and volcanoes and is at the centre of worrying shifts in critical climate drivers like the El Niño–Southern Oscillation. Defence will be a key part of how Australia copes with a future shaped by such realities, something its leadership ^[6] is already very conscious of.

In key ways these reviews are very different processes. The climate risk assessment will reportedly ^[7] be led by the head of the Office of National Intelligence, Andrew Shearer, and Defence will ‘provide input on defence-specific issues’. In other words, the climate risk assessment is being led by the intelligence community from within government. Because it is led by ONI, which is an internationally focused agency, we can surmise that it is an outward-facing assessment.

The defence review has a much broader remit ^[1]. It is being led by two independent commissioners, former defence minister Stephen Smith and former defence force chief Angus Houston, although they will be supported by the department. The review will examine ‘the Australian Defence Force’s structure, posture and preparedness in order to optimise Defence capability and posture to meet the nation’s security challenges over the period to 2032–33 and beyond’. To make policy recommendations for Defence, with its operational responsibilities both at home and abroad, it will have to account for climate impacts in both spheres.

The defence review is under immense time pressure. Smith and Houston have only until early next year to deliver. The timeline for ONI’s work isn’t clear. If the assessment is to usefully inform the defence review, though, it will have to move even more quickly.

So how might the climate risk assessment, the defence review and subsequent work be connected?

First, the findings of the climate risk assessment shouldn’t simply form a standalone section in the defence review. Climate risks should be integrated throughout. The government’s terms of reference are clear: the review ‘is to be informed by intelligence and strategic assessments of the most concerning threats which challenge Australia’s security’. The climate security risk assessment must be high on the list of these inputs.

Integration might involve dual-purposing some of Defence’s people and have them working on both the assessment and the defence review, something that is quite possibly already happening.

Defence probably also needs to do further thinking about the domestic components of the climate security challenge. ONI might be doing regionally focused work, but Defence as an operational organisation is being asked to confront climate impacts both at home and abroad.

Climate change is a systemic change whose immediate and long-term consequences will be felt across the huge range of Defence’s responsibilities. It must be part of the calculation across the review, not artificially (and erroneously) separated from ‘core business’.

Second, and once again because climate change is a systemic change, the defence review’s climate-change-related prescriptions should have a whole-of-government perspective. Like every aspect of this review, that will be tough because of the short timeframe. But any systemic challenge ^[8] necessarily overwhelms any siloed response.

Defence’s role in responding to climate change intersects with the responsibilities of a number of other government agencies, not only but most obviously elements of the Department of Home Affairs ^[9] and the Department of Foreign Affairs and Trade ^[10], and the defence review ought to reflect that. Time is clearly of the essence, so rough and ready integration is the only real option for now.

Third, while climate change considerations should pervade the defence review, they should nonetheless lead to unique recommendations and investments. For example, what climate intelligence capabilities are needed to pre-empt the worst possible outcomes? What existing or new exercises and wargames can be used to prepare for climate impacts? Defence is already grappling with the climate resilience ^[11] of its infrastructure, but what more needs to be done on that score?

One important area is the calibration of Australia’s disaster response capabilities. Before forming government, Labor flagged that it would consider setting up a civilian ‘national emergency task force’ ^[12]. The balance between responsibilities and resources in this area held by Defence, the broader government and society is contentious ^[13]. Addressing this issue requires consideration of how Defence can meet government and public expectations most efficiently, as well as of what is provided by other agencies and organisations.

Defence’s leadership team is acutely aware of this challenge. The service chiefs have continually reiterated that an increased, more frequent commitment of Defence to domestic disaster response activities is the new normal. At the same time, it has been widely acknowledged that there are significant ^[14] opportunity costs ^[15] to operational readiness and Defence’s workforce that come with these commitments. Helping to get the balance right would alone make the climate assessment and defence review worthwhile.

Under this umbrella, too, is the question of how the ADF responds to climate change impacts in conjunction with Australia’s regional partners. No country has enough capacity on its own—not Australia, and not our more populous but less wealthy neighbours. Identifying how certain assets can be shared and investments coordinated to build the capacity of key regional partners might be options here.

Fourth, the timeframes at play mean that both ONI’s security assessment and the defence review can only be an opening gambit. Calls for something like an ‘office of climate threat intelligence ^[7]’, properly integrated across government and drawing on expertise outside of it, reflect this ongoing need.

Both review processes simply don’t have time to thoroughly synthesise the breadth of domain and policy expertise that climate change implicates. And the climate science underwriting appropriately granular assessments of our regional and domestic future keeps evolving and improving. So, at least for Defence’s part of the puzzle, the defence review might address how the assessment will be iterated to inform Defence’s decision-making beyond this moment.

ONI’s climate risk assessment is likely to be exactly what it is labelled. The defence review will need to consider the insights gleaned from that assessment, among other analyses, and formulate sensible policy responses. Their respective authors need to get it right, together.