Report: Rising seas to put 1.5 million Australians at risk by 2050

Australia’s first National Climate Risk Assessment warns that rising sea levels and more frequent extreme weather will place more than 1.5 million people living in coastal communities at risk by 2050, and that no community in the country will be immune to cascading climate hazards.

The 72-page report, which examined three global warming scenarios — above 1.5°C, above 2°C and above 3°C — said Australia has already experienced warming above 1.5°C and that risks will intensify with each additional degree. It said coastal communities in northern Australia, remote settlements and the outer suburbs of major cities face particular exposure to rising seas and flooding if population levels remain at current rates.

The assessment forecast broader effects across health, infrastructure, ecosystems and the economy. It warned of rising heat-related deaths, degraded water quality from severe flooding and fire events, and the potential for a fall in property values amounting to A$611 billion ($406 billion; £300 billion). At 3°C of warming, the report said heat-related deaths in Sydney could rise by more than 400 percent and almost triple in Melbourne.

"Australians are already living with the consequences of climate change today," Climate Change Minister Chris Bowen said as the report was released. "It is clear every degree of warming we prevent now will help future generations avoid the worst impacts in years to come." The government released a national adaptation plan alongside the assessment, outlining how federal, state and local authorities can coordinate responses to rising risks.

The report described risks as "cascading, compounding and concurrent," saying extreme events will intersect and amplify harms. It flagged additional pressures on health services, critical infrastructure and emergency responders, while identifying heightened threats to primary industries and to biodiversity. Coral ecosystems such as the Great Barrier Reef off Queensland and Ningaloo Reef off Western Australia, already affected by record bleaching events, were identified as facing higher risks of bleaching and biodiversity loss as oceans warm.

The assessment arrives days before the government is due to announce an emissions reduction target for 2035. Australia has pledged to reduce emissions by 43 percent below 2005 levels by 2030. The government said its forthcoming 2035 target will be informed by advice from the independent Climate Change Authority.

Critics said the assessment underscores the need for sharper action. Amanda McKenzie, chief executive of the Climate Council, described the findings as "terrifying" and urged the government to commit to deeper emissions cuts. "Australia cannot afford a timid 2035 target when our own government data shows the catastrophic costs of inaction," she said, calling for faster, sustained reductions in climate pollution.

The report also highlighted the limits of adaptation and the economic trade-offs communities will face. It cautioned that, even with adaptation measures, costs will rise and some assets and ecosystems may remain highly vulnerable, prompting difficult decisions over protection, managed retreat and investment priorities.

The assessment provides a national snapshot of projected climate hazards and vulnerabilities, intended to inform policymaking at all levels of government. It catalogues near- and mid-century risks under the different warming scenarios and stresses the long-term benefits of early mitigation combined with coordinated adaptation.

Policy choices in coming years will shape the scale and distribution of harms, the report concluded, noting that the cost of inaction is likely to exceed the cost of measures to reduce emissions and strengthen resilience. The government said the assessment and adaptation plan will guide cooperative efforts to reduce risks and protect communities as it prepares its 2035 emissions target.