Understanding the Cascading Effects of Climate Change for NZ

The research, “Climate Change: The Cascade Effect: Cascading impacts and implications for Aotearoa New Zealand,” examines the cascading effects of climate change across sectors: urban systems (provisions of services and exchange in urban areas), water and utility networks (stormwater, wastewater, and water supply), and the financial services sector (insurance and banking) and their implications.

The cascading effect of climate change arises because of the interdependencies between natural and socio-economic systems that can strongly affect the community’s well-being, adaptive capacity of systems and infrastructures, and governance (Lawrence, Blackett, Cradock-Henry, & Nistor, 2018).

Lawrence et al. say, “Cascades affect the ability of individuals, governments, and the private sector to adapt in time before damaging impacts occur.”

The study examined the related literature and empirical studies on the:

• cascading climate change impacts and its governance implications for adaptation;
• narratives of cascading effects derived from workshops and interviews conducted, which include the stopbank breach cascades on the Hauraki plains,
• sea-level rise and coastal storm inundation that caused saltwater intrusions damaging groundwater pipes,
• drought cascades due to Wellington’s summer heat that resulted in a record number of leaks in drinking-water pipes and many other narratives.

Chapter 4.3 of the research report explains the “Systems mapping of cascading impacts.” It shows a causal loop diagram depicting how different types of climate change impacts, whether through extreme events or slowly emerging effects, can have similar interdependencies and feedback loops and generate similar cascades across other domains.

Other chapters discuss the implications on three waters (water supply, wastewater, and stormwater systems)

Little research has been done so far on the cascading effects of climate change across human systems and their implications for infrastructure and asset management systems.

The research report presents a good understanding of climate change’s cascading nature. It would be useful for governments, practitioners, and asset managers to enable them to design flexible yet robust climate adaptation actions that would reduce and avoid damaging impacts beyond communities’ ability to cope.