Rising seas could cost Australia $855 billion by 2100, study estimates

Sea level rise and storm surges could damage about 268,000 properties and 2 million hectares of Australian land by 2100 under a moderate-emissions scenario, a loss worth $855.1 billion in present-value terms, a new study estimates.

Under a high-emissions scenario, nearly 720,000 properties and 3.7 million hectares could be hit, with losses of up to $1.91 trillion, Shreya Dasgupta reported Oct. 1 in Mongabay. Researchers mapped areas projected to flood by 2100 and used real estate data to value the homes, farmland and infrastructure in them.

"Sea level rise may physically affect a large number of Australians who live near the coast, as the majority of Australians live within 50 kilometres of the coastline," said lead author Tom Kompas, a professor of environmental economics and biosecurity at the University of Melbourne.

Queensland has the most properties at risk, more than 93,000, followed by New South Wales and Western Australia. Among cities, the Gold Coast faces the largest potential losses, at $84.4 billion.

The study underpins a new report, "Rising Seas, Rising Bills," from the nonprofit Climate Council. Global sea level has risen at least 22 centimeters over the past century, and each centimeter of rise can cost about a meter of shoreline. "The science shows that the most extreme sea levels we see in a typical year now, will occur monthly by 2090," said report co-author Andrew Watkins, a climate scientist.

Kompas said the least costly option is to avoid building where the risks are highest and to restore coastlines.

This brief is based on reporting by Shreya Dasgupta, published Oct. 1, 2026, in Mongabay. Read the original: https://news.mongabay.com/short-article/2026/10/rising-seas-could-cost-australia-economic-losses-of-855-billion-study-finds/