Cascading climate change impacts and implications

Climate change is expected to have adverse impacts and implications for a range of human-environment systems. However, our understanding of the extent to which these impacts may propagate as cascades, compounding to form multiple impacts across sectors, is limited. Cascades result from interdependencies between systems and sub-systems of coupled natural and socio-economic systems in response to changes and feedback loops. The combined effects of interacting stressors may affect the ability of individuals, governments, and the private sector to adapt in time, before widespread damage occurs. We discuss the origins of cascading impacts thinking and present the results of an investigation of cascading impacts and implications in New Zealand. A participatory and collaborative approach was used through workshops and semi-structured interviews with sector informants, including engineers, local government staff, and financial risk managers and analysts from the financial services sectors. Qualitative data collection was combined with network and systems analysis to examine increased frequency of high-intensity rainfall events, sea-level rise and drought, across urban water infrastructure and the financial services, and the implications of cascading climate change impacts for governance. Results demonstrate that closer consideration of the combined effects of linked stressors can facilitate a better understanding of the scope and scale of climate change impacts. By using critical systems thinking in characterising and assessing how climate change impacts cascade across domains, we show the implications of cascades for their governance and reveal where climate change adaptation interventions might be focused. The research methods and insights into cascades provide a conceptual and practical basis for further development, which can inform the design of additional studies in other domains and jurisdictions.