Australia’s National Climate Risk Assessment: Identifying climate risk interdependencies within the infrastructure and built environment system for effective climate adaptation

Despite efforts to reduce greenhouse gas emissions, there are unavoidable impacts of climate change that are occurring now and will continue to unfold into the future. As the frequency and intensity of climate disasters increase, improving our understanding of climate risks will be critical for developing effective national climate adaptation actions. In recognition of the need for greater interdisciplinary and cross-sector collaboration to improve our understanding of systemic climate risks, a broad range of decision-makers across government and non-government organisations were engaged to identify Australia’s nationally significant risks through Australia’s first National Climate Risk Assessment (NCRA). In this paper, we describe the collaborative process developed for Australia’s NCRA and highlight the climate risk interdependencies identified for the infrastructure and built environment (I&BE) system. The I&BE system was chosen to illustrate the need to consider climate risk interdependencies, as this system’s sectors are heavily interconnected and fundamental to the functioning of critical infrastructure, essential services and supply chains. Using data collected through Australia’s NCRA, we illustrate how climate hazards create risks to individual I&BE sectors and how such risks aggregate, compound and/or cascade to form systemic risks. These systemic risks impact not only the I&BE system but also other systems, such as defence and national security, health and social support, and economy, trade and finance. Due to the high interdependencies of climate risks across sectors and systems, cross-sector collaboration is critical to address the interconnectedness of the systems and to develop effective climate adaptation strategies. A systemic approach to address climate risks will allow for response strategies that benefit multiple sectors simultaneously and reduce the likelihood of unforeseen negative compounding and cascading risks and maladaptation.