We must move Inland to Cessnock: Sea Level Rise in Newcastle, NSW, Australia

Climate science has been warning us about chronic, negative environmental changes for decades now. However, the scientists have been wrong on almost every front. Wrong in the sense that every prediction they have made has been shown to be mistaken. Climate reality, as it has unfolded, has been worse than their predictions. The science has been too conservative.

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Global temperatures are rising more rapidly than predicted and 17 of the 18 warmest years in the 136-year global record have occurred since 2001. A person born after February 1985 has yet to experience a month that was at or below the long-term average global temperature of the late 1900s until the mid-2000s. That is, 32 years of consecutive annual global temperatures above the long-term average and we are already on track for 33. Globally, there have been many more hot records than cold records in the first 17 years of this century. If there was no warming trend happening, there would be a 50-50 chance of a hot or cold temperature record. Such records, all things being equal,  would also be increasingly improbable. Yet, in Australia, for example, there have been 12 times as many hot records as cold ones between 2000 and 2016.

Sea level rise is faster than was predicted, with increasing heat both causing expansion of world oceans and the melting of land-based ice. The latest science has increased the projected extreme sea level rise to 2.5 metres by 2100. However, as the global temperature increases, the rate at which land-based ice melts is also likely to increase. The recent (February 2018) record warming in the Arctic, and concerns about the speed at which the Greenland ice mass will melt, have raised the spectre of a 7-metre sea level rise if Greenland’s ice melts into the sea. The question now is; how soon will that melt occur and with Antarctica melting as well, what will be the total sea level rise? As one of the world’s leading climate scientists has recently argued:

Greenland isn’t going to melt, it’s going to disintegrate. The forefront of research right now is forecasting how quickly that will happen and Greenland contains seven metres of sea level rise worldwide in its ice melt volume,

The latest information about Antarctica is equally disturbing. The rate at which the ice mass is melting is on the rise, and  “there has been a sharp increase, with almost half the loss coming in the last five years alone.”

While there are sceptics and denialists who will rant and rave about what I am saying from their home pulpits, I must point out to them that they, (mostly men over 50), will be long dead by 2100. This message is mainly for those born in the twenty first century as they will custodians of the Earth in 2100. There is also no point in planning for a future minimum sea level projection of 0.3 of a metre.  We must plan for the extreme and hope we never reach it.

In order to focus our attention on the issue of the impacts of climate change and sea level rise here are the Coastal Risk Australia scenarios for Newcastle NSW, my closest seaside city,  for the 2-metre and 6-metre projections for sea level rise. It is now possible to do these projections for almost any coastal region in the world. The first image shows the Newcastle-Sydney-Wollongong coast of the State of NSW, Australia.

Fig 1. Newcastle-Sydney-Wollongong coast of the State of NSW, Australia.

Sea level with Circle

It is worth remembering that sea level rise has happened before globally and on this coast of Australia. From a recent discussion of historical sea level rise:

Then between 18,000 and 8,000 years ago, global climate warmed, leading to rapid melting of the ice sheets, and seeing sea levels in the Australian region rising from 125m below to 2m above modern sea levels.

Tasmania was cut off with the flooding of Bass Strait around 11,000 years ago. New Guinea was separated from Australia with the flooding of Torres Strait and creation of the Gulf of Carpentaria around 8,000 years ago.

We found that 2.12 million square km, or 20-29% of the landmass – a size comparable to the state of Queensland – was lost during this inundation. The location of coastlines changed on average by 139km inland. In some areas the change was more than 300km.

Much of this inundation occurred over a 4,000-year period (between 14,600 and 10,600 years ago) initiated by what is called Meltwater Pulse 1A, a period of substantial ice sheet collapse releasing millions of cubic litres of water back into the oceans.

During this period, sea levels rose by 58m, equivalent to 14.5mm per year. On the ground, this would have seen movement of the sea’s edge at a pace of about 20-24m per year.

Fig 2. Newcastle Australia NSW, Sea Level Rise of Two Metres by 2100

Newcastle Wharf Road at 2 metres 2

On this projection you can see that the light Blue colour represents the extent of sea inundation at a 2-metre sea level rise. On closer inspection (below) you can see that much of Honeysuckle Drive (middle left) is submerged and many buildings facing the Harbour will be under water. The foreshore walkway adjacent to the Hunter River and the Port goes under as does a very large area of the portside Honeysuckle precinct. Areas where new buildings are proposed, such as on current public parking on the foreshore will be inundated.

Fig 3. Newcastle NSW Australia  Sea Level Rise of Two Metres by 2100 (Close Up).

Newcastle Close up 2 metre rise 2

Fig 3. does not indicate storm surge levels on top of the 2 metre sea level rise. In the flooding that occurred in 2007 in what has become known as the Pasha Bulker storm (Opening image is of the Pasha Bulker on Nobbys Beach, Newcastle), a surge of just under two metres entered the city of Newcastle and inundated 10,000 properties. Assuming the two metres of sea level rise, a similar storm surge in 2100 would cause 3-4 metres of inundation.

Fig 4. Newcastle Sea Level Inundation at 3-4 Metres

Newcastle 4 metre storm surge

Unfortunately for Newcastle, the Wickham transport interchange goes under water at 2.3 metres and with a 2 metre storm surge on top of a 2 metre sea level rise, the whole of the West end of Newcastle goes under water, deep water.

Wickham at 4 metres

While ‘buyer beware of sea level rise’ might not operate in the current market with respect to real estate values, nevertheless, people would like their assets to be passed on to future generations. There is also the question of living zones and planning for the future which is the responsibility of Local and State Government. The sea level rise to two metres above current levels is a known, science-based risk to the City of Newcastle within the next 100 years. Inaction, failure to plan and adapt will be colossal fiscal and human risk failures by the current generation towards the future. Our children and teenagers should be revolting right now. Their coastal parents are about to blow their inheritance in all respects.

To make matters worse, Newcastle planning authorities are currently using data from 2007 to do the assessment of sea level rise in Newcastle West.

They use the following sea level estimates to predict sea harbour increase:

In recognition of the potential for increases in sea level to increase the flood risk across Newcastle West, additional 1% AEP simulations were completed with the following sea / harbour level increases (Department of Environment and Climate Change, 2007).
0.4 metres (corresponding to the projected 2050 sea level increase); and, 0.9 metres (corresponding to the projected 2100 sea level increase). (NCC March 2017).

Clearly, the most recent data from climate science has made the planning for Newcastle West based on 2007 data, completely redundant. While the 3-4 metre storm surge scenario is bad enough, it could get worse. Some climate scientists are now modelling a flash melting of Greenland corresponding to an additional sea level rise of up to 3 metres. That, plus a storm surge, could see impacts of up to six metres by 2100. Such a scenario makes the current location of the City of Newcastle and its Port impossible for future security. Newcastle will have to be moved inland and it will have to be about 50 kilometres inland from where it is today.

Inland City Location

It is evident to many climate scientists that we have a ‘built-in’ 2 metre sea level rise by 2100 due to climate change. Global failure to stop even two metres of sea level rise suggests to me that we must also plan for a global Greenhouse temperature rise of 4 degrees Celsius or higher. Under these conditions, preventing further land-based ice meltdown will be impossible. Given that there is up to 80 metres of global sea level rise if all the world’s land ice melted, there will need to be planning for a new inland city above the 80-metre mark from sea level.

Cessnock, in the Hunter Valley, qualifies as it sits at about 100 metres above current sea level and the land goes even higher as one heads further inland (West).  In the Hunter Valley we should be thinking about the inland city of Cessnock as the Capital of the Hunter region.  It will link with other inland cities as the coast becomes nonviable. The ‘new’ city of Cessnock becomes an attractor for people who must leave the coast and the river valleys for safer ground. However, recent (2022) ‘inland’ flooding suggest that nowhere is ‘safe’ without extensive floodplain engineering to take climate warming enhanced “rain bomb” flood water well away from human communities. Cessnock still has the advantage that it will not be affected by high tide and sea-based storm surge flooding exacerbating inland flooding as it is well above any projected sea level rise and tidal influence.

Fig 5. Newcastle and the Hunter Region with a Five to Six Metre Sea Level Rise by 2100.

6 Metres Region 2

I have reached the conclusion in 2018, one day before my 65th birthday, that the 2-metre sea level rise for this Earth will happen by the year 2100. I am repulsed by this conclusion, as I know what havoc it will create for huge numbers of people world-wide. I have made it personal by focusing on my closest city, the birth place of my children. Their birth place will disappear at some point in the future, consumed by an ocean of water rising due to humanity’s own negligence in caring for this unique planet that houses life.

We still have time to stop the momentum pushing us towards a future possible 80 metre sea level rise and a world so hot that it is unimaginable. We must awake from a torpor that has prevented us from seeing the danger to our own future. How many more years of living in a heating world will it take? Frogs are smart enough to jump out of slowly heating water. Are we?

Breaking News:

  • In Newcastle-Maitland, NSW, the number of uninsurable addresses will rise five-fold by 2100, to nearly one in seven.
  • Wedged between the bush and the beach, the region faces escalating risk from both fire and flood.
  • In the waterfront suburbs of Carrington and Wickham, more than 99 per cent of addresses are expected to become effectively uninsurable.
  • If all climate risks were insured, Carrington would reach 90 per cent “uninsurability” in just 20 years.

See: https://www.abc.net.au/news/2019-10-23/the-suburbs-facing-rising-insurance-costs-from-climate-risk/11624108

2 thoughts on “We must move Inland to Cessnock: Sea Level Rise in Newcastle, NSW, Australia

  1. Pingback: Sea Level Rise in Newcastle NSW, Australia. | glennaalbrecht

  2. Because humans of current generations that have had school education are not taught to look ahead but only look short term and to be self indulgent about their immediate needs, they will continue to ignore and deny any facts that are given to them about climate change. Greed and denial as with past civilisations will lead the current crop of humans to suffer the same fate as many great past civilisations. Sad but inevitable as humans never learn from the past and most do not want any change to the current lifestyle that sees the rich determine the fate of the masses.

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