The Climate Council report said the most serious consequences of rising seas would be an increase in the frequency of coastal flooding and the retreat of shorelines.
Both these threats could cause massive damage in Australia, where the majority of the population live on the coast and where cities, towns and infrastructure are concentrated, it said.
"Coastal flooding is a sleeping giant," the report said, adding that the potential for economic damage was huge.
"More than USD 226 billion in commercial, industrial, road and rail, and residential assets around Australian coasts are potentially exposed to flooding and erosion hazards at a sea level rise of 1.1 metres, a high end, but quite plausible, scenario for 2100."
It was soon relaunched as the Climate Council -- an independent watchdog operating as a non-profit body funded by public donations.
Its report said the sea level had already risen and was still rising as a result of climate change, and was likely to climb 0.4 to 1.0 metre through this century.
But even a 0.1 metre rise in sea level increased the risk of coastal flooding, a potential problem in Australia where more than half the coastline is vulnerable to recession, it said.
The report said the combined impact of inundation and shoreline recession put thousands of homes and businesses and 27,000 to 35,000 kilometres of roads and rail at risk.
In addition, rising sea levels also posed dangers for many of Australia's species and natural attractions, including the Great Barrier Reef, due to the "drowning" of reefs, salt water intrusion destroying freshwater habitats and sandy beach erosion.
At particular risk of the rising sea levels were the coastal communities living on the Torres Strait islands in northern Australia, the report said.
