Global sea levels increased by 1.7 millimetres per year during the 20th century. Over the past 15 years, this trend has increased to approximately 3.2 millimetres per year. The rate varies significantly around Australia.
New South Wales
A sea level rise of 1.1 metres will put at risk between 43 900 and 65 300 residential buildings, with a current value of between $14 billion and $20 billion, and up to 4800 kilometres of roads, 320 kilometres of railways and 1200 commercial buildings, with an estimated value of up to $10.4 billion, $1.3 billion and $9 billion, respectively.
Local government areas of Lake Macquarie, Wyong, Gosford, Wollongong, Shoalhaven and Rockdale contain more than 50% of the residential buildings at risk in New South Wales.
Since the early 1990s, New South Wales has experienced a sea level rise of approximately 2.1 millimetres per year.
Northern Territory
A sea level rise of 1.1 metres will put at risk between 260 and 370 residential buildings, with a current value of between $100 million and $134 million, and up to 2045 kilometres of roads, 32 kilometres of railways and 24 commercial buildings, with an estimated value of up to $1.8 billion, $100 million and $500 million, respectively.
Darwin is particularly vulnerable to riverine flooding and more intense cyclonic activity. Impacts on infrastructure are expected to be extreme under a ‘business as usual’ climate scenario, including major threats to vital port infrastructure on the Northern Territory coast.
Since the early 1990s, northern Australia has experienced sea level rises of up to 7.1 millimetres per year.
Queensland
Queensland’s highly developed and populated coastal communities are likely to be significantly affected by the impacts of climate change. A sea level rise of 1.1 metres will put at risk between 48 300 and 67 700 residential buildings, with a current value of between $15.4 billion and $20 billion, and up to 4700 kilometres of roads, 570 kilometres of railways and 1440 commercial buildings, with an estimated value of up to $12.9 billion, $2.3 billion and $15 billion, respectively.
Since the early 1990s, northern Australia has experienced sea level rises of around 7.1 millimetres per year, while eastern Australia has experienced increases of around 2.0–3.3 millimetres per year.
South Australia
A sea level rise of 1.1 metres will put at risk between 25 200 and 43 000 residential buildings, with a current value of between $4.4 billion and $7.4 billion.
Nearly half (47%) of the South Australian coastline is sandy beaches, and more than half of these sandy beaches are backed by soft-sediment plains. Rising sea levels will make these coastlines significantly more vulnerable to shoreline recession and foredune destabilisation.
Since the early 1990s, southern Australia has experienced sea level rises of 2–7 millimetres per year.
Tasmania
A sea level rise of 1.1 metres will put at risk between 12 000 and 15 000 residential buildings, with a current value of $4 billion, and up to 2000 kilometres of roads, 160 kilometres of railways and 300 commercial buildings, with an estimated value of up to $4.5 billion, $700 million and $1 billion, respectively.
Since the early 1990s, Tasmania has experienced sea level rises of 2.6–3.4 millimetres per year.
Victoria
A sea level rise of 1.1 metres will put at risk between 31 000 and 48 000 residential buildings, with a current value of between $8 billion and $11 billion, and up to 3500 kilometres of roads, 125 kilometres of railways and 2000 commercial buildings, with an estimated value of up to $9.8 billion, $500 million and $12 billion, respectively.
Since the early 1990s, south-eastern Australia has experienced sea level rises of 1.3–2.8 millimetres per year.
Western Australia
Western Australia has the longest coastline of any Australian state or territory. A sea level rise of 1.1 metres will put at risk between 20 000 and 30 000 residential buildings, with a current value of between $5 billion and $8 billion, and up to 9000 kilometres of roads, 114 kilometres of railways and 2100 commercial buildings, with an estimated value of up to $11.3 billion, $500 million and $17 billion, respectively.
Since the early 1990s, the southern coast of Western Australia has experienced sea level rises of up to 4.6 millimetres per year, while the western coast has experienced increases of up to 7.4 millimetres per year.
Source: Australian Government Department of Climate Change and Energy Efficiency52