That hasn't been done.

A 2013 report titled 'Project AZ5220: Adaptation and planning strategies to mitigate the impact of climate change induced sea level rise, flooding and erosion at selected Defence sites', released under freedom of information laws, identified as high or very high risk in 2040 and 2070, 13 Defence sites, including the RAAF Base at Williamtown.

The report appears to form part of a two-stage study completed by Defence. The 2011 Study 1 involved a high-level screening of the likely risks associated with coastal and riverine flooding, and the potential for coastal erosion in 2040, 2070 and 2100. It recommended that more detailed examinations be carried out.

Of 38 significant Defence bases, 13 sites were then identified as being at risk.

Stage 2 involved more detailed assessments of coastal and riverine flooding and the potential for coastal erosion and was completed in 2013. The Stage 2 study confirmed that it 'should not be assumed that the other 24 sites included in the initial assessment are not at risk from the impacts of terrestrial flooding, coastal erosion or other impacts of climate change.'

That precaution was sensible given that the findings of Stage 2 were based on the now outdated 2007 findings of the Intergovernmental Panel on Climate Change. In 2014, the United Nations report 'Climate Change 2014 Synthesis Report Summary for Policy Makers' was released with its co-author Saleemul Huq, director of the International Centre for Climate Change and Development at Independent University in Bangladesh, warning that, "Things are worse than we had predicted in 2007, when the group of scientists last issued this type of report. We are going to see more and more impacts, faster and sooner than we had anticipated."

An executive report was prepared for Defence by AECOM in June 2018.

The AECOM report, 'Assessment of the Impact of Climate Change Induced Sea Level Rise, Flooding and Erosion at Selected Defence Training Areas and Ranges', was also released under freedom of information laws. It is a summary of the findings of Stage 2, and the redactions suggest things are far worse than the conclusions reached in the Stage 2 study in 2013.

It is worth noting that the Stage 2 report used a projection of 1.43 metres maximum sea-level rise by 2100 which by all reports is now entirely inadequate given that the Pentagon reportedly uses projections of 2 to 2.5 metres. A recent science paper 'Ice sheet contributions to future sea-level rise from structured expert judgment' suggests that two metres by 2100 is feasible.

What is disturbing about the findings of the Stage 2 report, itself based on the findings of the IPCC in 2007, are the impacts from and on marine flooding, estuarine flooding, site access and internal roads, pier and marine infrastructure, runways and aviation infrastructure, utilities, environmental assets and contamination of local areas . And the costs of adaptation were mounting even then.

It's particularly concerning that the now scientifically outdated Stage 2 report indicated that, 'Existing contamination and stored hazardous substances are at risk of mobilization into surrounding soils, groundwater and waterways due to climate change-induced inundation and coastal erosion at all assessed sites ... RAAF Base Williamtown ... have existing contamination which is at risk of inundation or coastal erosion. Inundation and erosion may cause the mobilization of existing contaminants into surrounding soils, groundwater and waterways. This may affect the human health of environmental values of neighbouring properties or waterways...".

At that time, RAAF Base Williamtown was classified as a medium risk to contamination from 2040-2100 but it remains unclear whether that risk level was elevated in the heavily redacted June 2018 AECOM report.

In 2018, the Senate Committee concluded that climate change is "a current and existential national security risk", one that "threatens the premature extinction of Earth-originating intelligent life or the permanent and drastic destruction of its potential for desirable future development".

Documents released also confirm that late in 2018 the Chief of Defence, Angus Campbell, met with David Spratt and Ian Dunlop. They are authors of the report 'What Lies Beneath - the Understatement of Existential Climate Risk' and just this month made headlines with their report which suggests that there is a high likelihood of human civilization coming to an end starting in 2050. Defence officials met with Spratt and Dunlop with the objective of better understanding the security implications resulting from the effects of climate change.

The work of Spratt and Dunlop is focused on the question of whether the Australian government has a realistic grip on the existential risk of climate change, including from a global national security perspective. Their conclusion, as outlined in their published material, is that in general they do not.

Kellie Tranter is a lawyer, researcher and human rights activist.