Hunter & Central Coasts New South Wales - Vulnerability to climate change impacts: Report to the Department of Climate Change and Energy Efficiency, Australia

Abstract

This study assesses the vulnerability of the NSW Central Coast and Lower Hunter region (NSW) to the impacts of climate change. The primary objective was an interdisciplinary appraisal of the vulnerability of infrastructure and natural ecosystems to the impact of sea level rise, storm surge and intense rainfall. It uses climate change projections produced by the IPCC and CSIRO for the years 2030 and 2070. Under this scenario the projected value of sea level rise in 2030 is 146mm and in 2070 it is 471mm, relative to 1990 levels. In an effort to assess the vulnerabilities that might be faced by the region, this investigation undertook a past-present-future landscape analysis to allow a more integrated understanding of changing landscape-scale social-ecological parameters. The investigation also examined alternative future landscapes that minimised adverse impacts. Predicted future landscapes for 2030 and 2070 showed considerably larger areas of urban settlement than at present, and reductions in natural ecosystems areas and beach/dune areas. Ecosystems vulnerable to future urban expansion include coastal heath, coastal banksia/mahogany complex, scribbly gum/banksia complex and paperbark forest. Seven coastal beach-dune areas are vulnerable to considerable beach recession by 2070. There is a 'threshold' risk that 2070 sea level rises combined with a storm event could cause a total breach of a dune area causing enormous disruption. The area occupied by human built environment will increase in the coming decades. Without adaptation, it's expected the areas affected by climate change will also increase. In 2030 the area of human built environment vulnerable to combined sea level rise and flood extremes is likely to be about 6,316ha for the Newcastle Local Government Area (LGA), 2022ha for the Lake Macquarie LGA and 3,399ha for the Wyong LGA. As an example, an alternative future landscape for 2030 was designed and analysed. It sought to reduce the vulnerability of urban areas and ecosystems and demonstrates that vulnerable urban areas could be reduced by 46.4 per cent, while protecting coastal ecosystems as buffers. Other alternative future scenarios should be evaluated to assess landscape change and vulnerability trade-offs. An analysis of social vulnerability suggests that concentrations of socio-economic vulnerability within the study area were generally associated with retiree communities and Housing Commission neighbourhoods. The study finds that the landscape futures method is a useful approach for the integration of sociol-economic and ecological vulnerability information. It also revealed a range of data issues that will need to be addressed in the future.