Science and climate modelling has been informing people living in Australia's coastal zones that global warming-induced sea level rises, along with changes in east & west coast current speeds, more erosive wave patterns & increased flooding, will make living along the coastal fringe highly problematic the deeper the earth moves into this era-long climate change.
Coastal residents have been warned every year since at least 2006 and 2022 is no different.
This is the message in 2021-22.
What the NSW Government’s ADAPT NSW has to say about climate change-induced sea-level rise along the state’s coastline:
Projected sea level rise along the NSW coast
There is a direct relationship between climate change and sea level rise. As our climate warms, sea level rises mainly because of thermal expansion (when water warms up, it expands) and melting of snow, glaciers and ice caps (which increases the volume of ocean water). However, sea level rise is also effected by local oceanographic processes (e.g. changes to ocean currents) and changes to land levels.
Sea level rise is projected to accelerate over the 21st century. The most recent sea level rise projections are from the Intergovernmental Panel on Climate Change (IPCC) 6th Assessment Report. The IPCC predict a likely sea level increase on the central NSW coast of
between 0.21m and 1.06m by 2100, and
between 0.28m and 1.95m by 2150.
This is dependent on the level of future greenhouse gas emissions.
IPCC modelling suggests slightly higher sea level rise to the north of the state and slightly lower to the south. These projections do not include processes associated with the melting of ice sheets which for NSW could result in sea level rise of up to 2.3m by 2100 and 5.5m by 2150.
In the longer term, the IPCC show sea level is committed to rise for centuries to millennia due to continuing deep ocean warming and ice sheet melt, and will remain elevated for thousands of years.
If warming is limited to 1.5°C, global mean sea level will rise by about 2 to 3m.
for 2°C, 2 to 6m is expected, and
for 5° 19 to 22m is expected.
This is the current seawater inundation scenario message in Predicted Coastal Flooding Resulting from Climate Change, based the IPCC Sixth Assessment Report Update 2021.
Examples from Coastal Risk Australia 2100 interactive mapping tool using IPCC scenarios for the period 2021 to 2100.
Sometime in the next 79 years this is what two small coastal towns will probably look like from the air.......
Ballina, New South Wales - blue area seawater inundation at 0.8m
The Daily Telegraph on 18 January 2022:
The Coastal Risk Map shows what Australia will look like if sea levels rise due to climate change, showing how much extra water will filter into our cities and suburbs and the impact it will have on our way of life.
The map was originally created by spatial mapping company NGIS with non-profit partner Frontier SI in 2015, but has recently been updated with new data from the United Nations Intergovernmental Panel on Climate Change’s Sixth Assessment Report.
The sea level projections show that if greenhouse gas emissions are moderated, the ocean may rise by 0.84m by 2100.
But a global rise approaching 2m by 2100 and 5m by 2150 would be possible under a very high greenhouse gas emissions scenario- much higher than first thought.
NGIS Executive Director Nathan Eaton said the aim of the map was to illustrate the data and give Australians a better understanding of how sea level rises could impact their lives.
“Previously the map showed a rise of 0.74m at it’s lowest, that’s since changed to 0.84m,” Mr Eaton said.
“Now less than a metre doesn’t seem like a massive difference to someone, but in low lying areas, even 10 centimetres can make a huge difference.”
Geobiology, archaeology and sea level expert Dr Ben Shaw said the map could be a “wake up call” for authorities on the urgency of curbing climate change.
“It’s phenomenal to see how impacted parts of Australia will be … a real concern for people living in Sydney, across NSW and around Australia, our coastline will look very different and there could be a serious environmental disaster,” Dr Shaw said.
“We will see the impacts of climate change regardless, but if we put the policies and strategies in place now to curb it … it can make a huge difference over generations and decades to avoid something like this.”
“Otherwise things like our water sources, our infrastructure, our suburbs and way of life may have to change drastically.”
The Daily Telegraph has analysed the Coastal Risk Map to see just how much a five metre rise in sea levels would impact NSW - here’s what we found and how it will affect you.
HOW NSW WILL CHANGE IF SEA LEVELS RISE
Under the current worst case projections, if sea levels rise by 5 metres by 2150:
FAR NORTH COAST (Tweed Heads and beyond down to Coffs Harbour)
Most of Coffs Harbour will feel the impact of rising sea levels. Residents living in the vicinity of Boambee Beach out to North Boambee Valley and in and around Park Beach will be impacted, with water set to flow into the CBD.
Moonee Beach and significant sections of Woolgoolga and Emerald Beach will disappear or become a small set of islands as water flows above the shoreline. Other beachside areas like Red Rock, Wooli and Sandon will be overrun and become lakes or bays.
A major new lake system will be established flowing more than 60km inland from Yamba to Grafton if sea levels rise.
Areas like Grafton itself, Cowper, Townsend Harwood Island, Talumbi and Yamba and Wood Head will cease to exist, forming a large lake with a the village of South Arm in the centre.
A similar large harbour will be carved out between Evans Head and Lennox Head, swallowing up Ballina, Wardell, Broadwater, Coraki, Woodburn and as far down as Bungawalbin, with waterways also swelling to impact Lismore.
Directly along the coastline, the enclave of Byron Bay will be completely awash, as will every other settlement stretching up to Kingscliff and past the Queensland border.
Water will overtake Brunswick Heads, New Brighton, Pottsville, Hastings Point, Casuarina all the way up to Tweed Heads, flowing inland to inundate areas like Murwillumbah, and creating another large lake.
Down near Byron, Mullumbimby will also be severely impacted.
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