AUSTRALIA

Sea level around Australia has been rising, and the rate has accelerated in recent decades.

The National Climate Risk Assessment (NCRA), released in September 2025, is Australia’s first nationally comprehensive assessment of climate change risks across systems such as communities, the economy, infrastructure, health, and the environment. It was prepared by the Australian Climate Service (a partnership of CSIRO, Bureau of Meteorology, Geoscience Australia, and the Australian Bureau of Statistics) under multiple warming scenarios and includes the hazard of sea-level rise and its implications for Australian coastal communities. Based on the report and previous data sources, projections include:  

Observed Change (1975-2025):

Sea level around Australia has been rising, and the rate has accelerated in recent decades. While regional variability exists along the Australian coast, the satellite-era global mean sea-level rise has been around ~3 mm/year. (Source)

Near-term projection (to 2050):

By 2050, the assessment gives relatively constrained rises under plausible scenarios, of order tens of centimetres, commonly quoted around ~0.14 m (14 cm) for lower-warming assumptions, with larger values if warming continues. Sea-level-driven coastal flooding events (including “high-tide” and storm inundation) are already more frequent and will increase sharply by mid-century (SOURCE). 

Longer-term projection (2050→2100+):

The National Climate Risk Assessment highlights scenario ranges such as ~0.32 m by later this century under ~2°C-type futures and ~0.54 m (or more) under ~3°C futures, with higher plausible upper-end values (approaching ~1 m in some planning scenarios). Because ice-sheet processes are uncertain, the long-term (century+) risk includes substantially larger rises if high emissions continue. These different futures translate into major jumps in coastal flood frequency and the number of Australians exposed (millions more by 2050–2090 under higher rises). (SOURCE)

Impacts

Australia’s 2025 National Climate Risk Assessment identifies sea-level rise as a significant and accelerating threat to coastal communities, infrastructure, and the economy. Even modest increases, already locked in for the coming decades, significantly lift the frequency and severity of coastal inundation, erosion, and storm-surge impacts.

Property & Homes: 

Sea-level rise is expected to drive large losses in coastal property value, higher exposure to flooding, and increased damage to homes and buildings. By 2050, around 1.5 million Australians could be living in high-risk coastal areas. Some coastal properties are already facing reduced valuations and development constraints due to local risk-based planning overlays. Potential property-value losses across Australia are estimated at AUD 611 billion by 2050 and AUD 770 billion by 2090 due to climate-driven risks.

Insurance & finance:
Insurance premiums in exposed areas are rising sharply, and some coastal properties risk becoming uninsurable or under-insured as flood and erosion risks escalate. The number of “very high risk” homes (coastal/sea-level rise risk) is projected to be “one million homes” by 2050 in zones deemed very high risk or effectively uninsurable. Banks and investors are increasingly integrating physical-risk assessments into lending and portfolio decisions, heightening the risk of stranded assets in vulnerable coastal zones.

Community planning & infrastructure:
Local and state governments are beginning to update zoning, building codes, and development controls to prevent new high-risk construction and protect critical infrastructure such as roads, wastewater systems, and ports. The NCRA stresses the need for planned retreat, elevation, and protection works, as well as resilient urban design, to avoid locking in future losses.

Coastal geography & ecosystems:
Rising seas are already contributing to coastal erosion, wetland loss, saltwater intrusion into groundwater, and degradation of cultural and natural heritage sites, particularly in low-lying and Indigenous coastal communities. These geographic changes will intensify without adaptation. By 2090, coastal erosion events may occur 14 times more often than now (SOURCE). 

Adaptation Plans 

Australia’s National Adaptation Plan sets out a coordinated national framework for adapting to physical climate risks, including sea-level rise (not solely sea-level rise, but part of it).

It sets out a vision of a “well-adapted Australia”, and outlines actions across seven key systems (infrastructure & built environment; communities; economy, trade & finance; natural environment; health & social support; primary industries; defense & national security).

In relation to coastal hazards and sea-level rise specifically, the Plan refers to existing and planned efforts such as:

• Integrating sea-level rise and coastal hazard risk into planning and infrastructure frameworks; for example, the Coastal Hazards Adaptation Strategy guides sea-level benchmarks and identifies whether areas should be protected, modified, or withdrawn/retreated. 
• Improving climate information and services for decision-making (so local governments, states, councils can reflect sea-level rise in land-use, zoning, building codes) 
• Supporting local and regional coastal adaptation projects through targeted funding, such as the Coastal and Estuarine Risk Mitigation Program, which funds nature-based defenses, coastal flood mapping, and protective infrastructure upgrades.
• Investing in resilience and risk-reduction through the Disaster Ready Fund, which provides up to AUD $1 billion over five years for projects including coastal flood protection and infrastructure strengthening in vulnerable communities.

Investment so far is in the billions of AUD, with $3.6 billion since 2022 and AUD $9 billion to 2030, but a clear cost for sea-level-rise adaptation alone is not published in the Plan. In its 2025-26 budget, the government committed an additional AUD $354 million to adaptation measures and AUD $632.5 million over the medium term to climate change adaptation and disaster resilience. 

On the local government side, councils in Australia are expected to spend more than AUD $2 billion over the next five years on climate-resilient investments broadly (which would include coastal hazard management) with estimated avoided costs of up to AUD $4.7 billion by 2030.

The adaptation effort is multi‐decadal: planning reforms, infrastructure upgrades, retreat/relocation strategies will play out potentially into the mid- and late century.

This Post was submitted by Climate Scorecard Australia Country Manager, Jessica Gregory.