Nationwide economic impacts of sea level rise and storm surge from global warming in Australia

Abstract

Driven by global warming and thermal expansion of the oceans, ice loss from glaciers and ice sheets will continue to increase sea levels and the risk of storm-surge, threatening coastal regions worldwide. This study presents the first national-scale assessment of SLR/S impacts on land use and assets across Australia, covering 1,156 coastal sub-regions in six states and the Northern Territory under RCP4.5 and RCP8.5 scenarios. The analysis integrates physical and economic impacts across 10 aggregated land-use categories. By 2100, under RCP4.5, SLR/S is projected to affect 267.5 thousand properties and 2.0 million hectares (ha) of land, resulting in present-value damages of $855.1 billion, including $274.3 billion in property losses and $580.7 billion in land-use losses. Under RCP8.5, impacts increase to 719.6 thousand properties and 3.7 million ha, with total damages of $1,909 billion, comprising $705.7 billion in property losses and $1,203 billion in land-use losses. The results reveal substantial spatial heterogeneity in physical exposure and economic impacts across Australia. Average annual SLR/S damages are estimated to reduce national GDP by 1.05–1.39% under RCP4.5 and 2.26–3.0% under RCP8.5. These estimates are conservative, as they exclude additional losses to environmental assets, cultural heritage, and other infrastructure not captured in the assessment.