Australia's coastal land vanishing as sea levels rise, costing billions

Key facts

• Australia faces over $855 billion in projected economic losses by 2100 due to coastal flooding from rising sea levels.
• More than 267,000 coastal properties and 2 million hectares of land are forecast to be damaged by 2100.
• Queensland, NSW, and Western Australia are the states with the highest number of homes at risk.
• The Gold Coast is projected to suffer $84.4 billion in economic losses.
• The report models impacts under the RCP4.5 climate scenario, projecting a 2.7C global temperature rise by century's end.
• Agricultural land damage could affect food security, with 619,713 hectares of farming land at risk.

Grazier Peter Lake has witnessed his Clarence Valley farm in New South Wales become increasingly vulnerable to flooding and rising sea levels since moving there in 2007. Lake noted that the amount of flood-free land on his 130-acre property has significantly decreased, particularly after the major flood in 2022, impacting his ability to grow fodder crops and raising concerns about the long-term viability of his property.

A new report by the Climate Council forecasts that Australia could face over $855 billion in economic losses by the end of the century due to coastal flooding, with more than 267,000 properties and 4.9 million acres of land at risk as sea levels rise. Queensland, New South Wales, and Western Australia are identified as the states with the highest number of homes vulnerable to flooding.

The report highlights the Gold Coast as the most exposed urban area, with projected economic losses of $84.4 billion. Melbourne's low-lying areas around Port Phillip Bay and the Yarra River are also significantly at risk. The analysis, based on the RCP4.5 climate scenario projecting a 2.7C global temperature increase, suggests that the estimated costs of property and land use damages are conservative and do not account for coastal erosion or significant ice sheet melt.

Co-author Professor Tom Kompas emphasized that the projected agricultural losses, potentially affecting 1.5 million acres of farmland, could lead to food security issues. Sea levels have already risen by over 22cm globally since 1900, with human-caused global heating being the primary driver since 1970. An additional 14cm rise is anticipated in Australia by 2050, increasing the frequency of permanent inundation. Kompas stressed the importance of immediate planning and adaptation, including avoiding construction on flood plains.