Tom Kompas, Tuong Nhu Che, R Quentin Grafton
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.