Great Barrier Reef: No Basis for Alarming Sea Level Fear, Second Report Finds

[Post corrections 11/22/21 12:18 Pacific time. The photos were out of order and assigned the wrong captions. This is fixed. There was a spelling error in the title now fixed.~cr]

By David Mason-Jones

Analysis of a second tide gauge in the waters of the Great Barrier Reef has confirmed the results of an earlier study at the Port of Townsville and nearby Cape Ferguson. The new Report focusses on the tide gauge at Cooktown on the Queensland coast, facing the Reef lagoon.

Figure 1. The Cooktown storm surge tide gauge (arrowed) located on the wooden-decked wharf prior to its restoration in 2015. (Photo 44740 from the Cultural Atlas of Australia.)  

Researcher and author of the Report, Australian scientist Dr. Bill Johnston, states, “Claims that anthropogenic global warming is causing sea level to rise, particularly in the northern sector of the Great Barrier Reef, are unfounded.

“What the raw data from the Queensland Government Ports Authority website shows is an apparent rise of .036 metres per decade at Cooktown. This can be simplistically derived by comparing the start point of readings at Cooktown with the end point of the series over a period of years. However, such a method of analysing data by just comparing a start point with an end point is naïve. Instead, the mis-identified trend ‘found’ by such poor analysis is easily shown to be a series of sudden step-ups in the data, none of which is attributable to a change in climate.  

“It is misleading that researchers should label a series of step changes like this as a steadily rising trend,” says Johnston.  

Cooktown lies in the Tropics and, as a consequence of the combined effects of siltation from the Endeavour River and violent winds and sea surges from cyclones – all normal events in this part of the world – a major dredging program was implemented adjacent to the wharf to allow continued access by vessels. In this process 108,000 cubic metres of silt was dredged right next to the wharf in 1997. This caused the pylons on which the sensor was attached to settle 40 mm into the bed of the river. Interestingly, dredging of 26,000 cubic metres further away from the wharf in 1999 to create a turning bay for ships, caused no pylon sinkage.

Following Tropical Cyclones Ellie and Hamish in early 2009, further dredging near the wharf resulted in 37 mm additional sinking. In 2015 there was more dredging associated with a wharf refurbishment where the wooden wharf was strengthened and re-decked with a new composite structure capable of allowing small trucks to load and unload. This resulted in a further 32mm sinkage. The combined effect of all this dredging and extra loading was a massive 109mm settling of the pylon, thus making the sea look as if it was rising.

“All these sudden step changes can be seen clearly in the analysis,” says Johnston. “They stand out when they are correlated with government records of dredging and other work. The full research Report deals with several additional factors to those outlined here.”

The Queensland Government has taken time-series aerial photographs of the coast including around the Port of Cooktown and these are publicly available from Queensland Government archives. Aerial photographs taken in 1969, 1974, 1979, 1983, 1987, 1989, 1991, 1994 compared with high-definition Google Earth Pro Satellite imagery show no signs of tidal encroachment at Cherry Tree Bay just east of Cooktown across the peninsula.

Dr. Johnston says, “Ground-truthing of the satellite data shows the scary claims of rapid sea level rise in the Reef are illusory. The Mean Surface Level of the water in relation to the terrain of the coast has not changed. Historic aerial photographs, and satellite imagery show this.”

Figure 2. Aerial photograph of Cherry Tree Bay, east of Cooktown taken on 11 September 1969 overlaid on Google Earth Pro (GEP) Satellite image for 16 September 2018; upper-left, GEP opacity 0%, 50%; lower-left 75%, 100%. Tidal wetting fronts, littoral zones, rocks and shoals show no encroachment or change in exposure due to rising sea levels over the intervening 49-years.

Despite this, the Great Barrier Reef Marine Park Authority (GBRMPA) maintains its claim that, due to global warming, sea level in the Reef is increasing and that the fastest rate is in the northern sector.

The notion that the sea may be rising more rapidly at Cooktown than at other places along the Reef is fanciful. 

The Intergovernmental Panel on Climate Change (IPCC) predicts sea level will rise by around 26 to 29 centimetres over the next 9-years, that is, by 2030. For this IPCC prediction to eventuate in the waters of the Reef in just nine years, the sea had better hurry up because the prediction now requires an annual rise of more than three centimetres per year. And if the sea delays rising for just another 12 months, the required annual rate will need to lift to 3.5 centimetres per year. With no evidence at all of this happening in the Townsville and Cooktown areas, it is just mind-boggling to grasp the idea that the IPCC prediction will be fulfilled.

From where do these guys get all this stuff?

On what hard data do they base their claims?

Do they ever deeply question their assumptions?

Dr. Johnston’s full Report, including a downloadable PDF with graphs and full tables of data and full descriptions of methods used can be found here:

An exasperated Johnston states, “As with almost anything to do with claims about Australia’s iconic Reef, the more you look at the data, the more questions you have.  

“The research at Cooktown provides no evidence for the belief in rapid sea level rise and this backs up my previous research around Townsville,” he says.  

Political grandstanding, emotional media releases, uninformed media reportage and commentary about the health of the Reef is not justified. Data at Cooktown shows that extreme claims about what has happened in the past, together with extreme predictions about what will happen in the future, are false and should be called out.  

David Mason-Jones is a freelance journalist of many years’ experience.

Dr. Bill Johnston is a former NSW Department of Natural Resources senior research scientist and former weather observer.

For the full research Report go to:

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Clyde Spencer
November 21, 2021 2:13 pm

… Alarming Sea Fevel Fear, …

Title Typo: Fevel

Reply to  Clyde Spencer
November 21, 2021 2:31 pm

Well, just change it to Sea Fever Fear and it’s all good.

Aren’t the oceans boiling? Doesn’t that create sea level rise?(Jus’ messin’ wid ya, Clyde.)

Reply to  H.R.
November 21, 2021 5:12 pm

Nah, it is so acidic that just swimming in the sea melts away excess fat !

Reply to  Clyde Spencer
November 21, 2021 6:26 pm

S/b Fee Level Fear.

mark stevens
Reply to  Clyde Spencer
November 22, 2021 7:40 am

seems to be a fitting term 🙂

November 21, 2021 2:14 pm

If the sea level fails to rise, you have to drop the tide gauge down a little bit each year.

Reply to  nicholas tesdorf
November 21, 2021 2:24 pm

And it’s pretty sad when they have to cover it with sand.

John K. Sutherland
November 21, 2021 2:46 pm

Dr. Johnston is a ‘former’ this, and a ‘former’ that. Lucky him, or he’d be scrambling for a new job after daring to point out that the King has no clothes.

Rud Istvan
Reply to  John K. Sutherland
November 21, 2021 3:35 pm

Peter Ridd

Reply to  John K. Sutherland
November 21, 2021 8:11 pm

Young people raising families are very susceptible to extortion so it behooves older scientists to carry the torch. Also, older scientists generally have a better handle on the incomprehensibility of complex systems. Young people are good at math, old people are good at ecology (David Suzuki excluded)

Reply to  John K. Sutherland
November 22, 2021 1:50 am

These days you need to be a former to form a own opinion.

Otherwise the great soviet will punish your wrongthink.

Rud Istvan
November 21, 2021 2:47 pm

Anyone familiar with a bathtub knows the seawater cannot be rising higher on the northern Barrier Reef than on the southern end. Proof positive the the measurements are problematic from general principles.
Good to have the physical explanation on top of the general principle.

As an aside, any tide gauge measurement less than about 60 years is suspect because it does not adequately compensate for the nodal lunar tide cycle of 18.6 years, which causes a variation of about 30 cm.

Reply to  Rud Istvan
November 21, 2021 3:00 pm

Indeed. If you want to say that the sea level rise was greater here, than it was over there, you should be prepared to say why.

Reply to  commieBob
November 22, 2021 5:51 am climate change of course.

Zig Zag Wanderer
Reply to  Rud Istvan
November 21, 2021 3:39 pm

Sea levels are rising twice as fast as everywhere else, everywhere. This is Climate Scientology in a nutshell.

Tony Taylor
November 21, 2021 2:48 pm

Expect that fact to be swept under the whitewash.

Reply to  Tony Taylor
November 21, 2021 6:43 pm

They don’t use whitewash on the Stevenson screen any more, they use latex paint.

November 21, 2021 2:48 pm

There are people who want the sea level to rise….the glaciers to melt….the storms to grow worse…the forests to burn…why?….because they have political and economic reasons… and pseudo-science is merely a means to an end for these people…..whatever it takes….they will do it.

Rud Istvan
Reply to  Anti_griff
November 21, 2021 3:39 pm

They will try, as a lot of grant research and renewables money is at stake. But eventually the disastrous costs they seek to impose will be their undoing. The remaining question is whether the guillotine will be part of the eventual resolution.

Thomas Gasloli
Reply to  Rud Istvan
November 21, 2021 4:30 pm

Disastrous cost won’t necessarily result in their undoing, see Venezuela, Zimbabwe, North Korea, ….

Rod Evans
Reply to  Thomas Gasloli
November 21, 2021 11:28 pm

You forgot to add California to the list Thomas…..

November 21, 2021 3:37 pm

At that rate the oceans will be 3,600 meters deep in one million years. If my math is correct.

November 21, 2021 3:51 pm

What are Sea Fevels?

probably another deadly sea creature from Australia

Zig Zag Wanderer
Reply to  chickenhawk
November 21, 2021 6:13 pm

They will never survive the drop bears, though. Those critters are devious, and can turn amphibious!

Reply to  Zig Zag Wanderer
November 21, 2021 7:34 pm

But the drop bears now are clearly in furious conflict with the lift bears! Which of these two devious breeds will win???

Steve Case
November 21, 2021 4:07 pm

The Intergovernmental Panel on Climate Change (IPCC) predicts sea level will rise by around 26 to 29 centimetres over the next 9-years, that is, by 2030.

That’s ten times the usual reported rate of sea level rise of around 3mm/year. Obviously somebody misplaced a decimal point and nobody bothered to check the arithmetic.

Reply to  Steve Case
November 21, 2021 5:17 pm

Same guy that said Himalayan glaciers would be gone by 2035?

Steve Case
Reply to  BobM
November 21, 2021 7:11 pm

Good one!

Reply to  Steve Case
November 22, 2021 3:48 am

It seems likely that someone simply replaced the word ‘millimeter’ with ‘centimeter’. That then became a “fact too good to check”.

November 21, 2021 5:23 pm


The 2 illustrations (or their descriptions) are mixed up.

November 21, 2021 6:12 pm

Foreigners and academics claim that the Great Barrier Reef is in trouble, Australians who live along the Eastern coastline near the GBR know better as do tourists who travel to explore it’s wonders.

And we also understand that coral reefs have life cycles and at any given time there are areas in decline, areas regenerating and most areas are thriving with life.

Of course the GBR is world famous, rarely do the many other coral reefs around the world get mentioned, including the West Coast of Australia

November 21, 2021 6:25 pm

Clearly, any study needs to compare the tide gauges of nearby stations.
Both long term trends and individual storm events.
Once compared, all differences must be reconciled.

November 21, 2021 7:03 pm

Highest Astronomical Tide (HAT), is the theoretical maximum still water height.
However, the water is very rarely still.
The concept of storm surge is the extra height from all the “stormy” stuff.
Here in Melbourne, in southern Australia the storm surge may add 0.2-0.3m on top of tide levels.

But in North Queensland the storm surge could be in the 1.5m to 2.0m range

The HAT at Cooktown is 1.72m (Australian Height Datum = AHD)
On April 2014 Tropical Cyclone Ita caused a 1m storm surge at Cooktown, BUT it was added to the low tide of the day. The high tide of that day only increased by 0.6m to 1.3m AHD.

So in a tropical cyclone, the high water level didn’t even reach the HAT.

Just adding Alarmist theoretical SLR to each location is BS.
To calculate inundation changes from Climate Change a statistical analysis of all events is required at each location

Bill Rocks
Reply to  waza
November 22, 2021 6:47 am

I remember studying “wave setup in the nearshore zone”, during post-graduate course in coastal oceanography. Ocean water height varies along coastlines for many reasons and on many time scales. I even enjoyed the mathematics.

November 21, 2021 7:28 pm

The reef is dead. James Cook University says so. I don’t know why people even bother to study this stuff anymore, and there is certainly no point in visiting.

Reply to  Chris
November 21, 2021 7:30 pm You can even see how the exposed coral has died. The coral has obviously been exposed due to rising sea levels.

Moderately Cross of East Anglia
Reply to  Chris
November 22, 2021 1:26 am

Oh, the silence of the Clams…

Reply to  Chris
November 22, 2021 8:27 am

‘Every time we walk on these corals, they seem to be less healthy that they were before. Fortunately, there seems to be less damage on the reefs we can’t walk on, but surely they are weakened by warming as well.’

Reply to  Chris
November 21, 2021 7:48 pm

I went skiing this morning and it was wonderful to have few people on the slopes, no lines for the first couple of hours. I imagine it’s easier to find quiet spots at GBR.

Reply to  Chris
November 21, 2021 8:51 pm

President Obama visited Queensland, Australia to attend a G20 Meeting and he visited a university to address an audience of students, on climate change, and he said that he was very concerned about the deteriorating condition of the GBR and intended to arrange a visit for his daughters to see its before it was completely ruined.

That was about seven or eight years ago from memory.

November 22, 2021 1:55 am

Sea level rise is surely good news for the GBR, deeper water is cooler water.

November 22, 2021 2:03 am

Rising seas would actually protect the reef anyway, as it is exposure to sunlight at low tides that causes bleaching

November 22, 2021 12:53 pm

Sailing that part of the world years ago, we relied on charts drawn by iron men from the early 1800’s. And on these charts in quite exquisite detail are the location of rocks, because of the hazard to shipping.

And as a sailor you pay them a lot of attention. A lot. And on these charts are a special class of rocks, called drying rocks. These are rocks that are visible only at low water, and covered at high water. Typically a rock is marked with an “x” and a drying rock with an “x“.

Surely there must have been some barely drying rocks from the 1800’s that are today fully underwater, but that is not what we found. In any area that we were there long enough to go through a tide cycle, or in any area where the tidal range was small, the drying rocks were still drying rocks.

This begs the question. Why bother with tidal gauges? Survey the drying rocks from the Admiralty charts drawn years ago. A statistical analysis will show you how much if any sea level has changed. Our survey showed no significant change.

Reply to  ferdberple
November 22, 2021 8:04 pm

Thanks for that ferdberple. It’s a fabulous anecdotal piece of evidence. I’ll certainly be using it in future. Have you seen the paper we have presented about the 1871 scientific expedition to Cape Sidmouth in which they measured sea surface temps every daylight hour all the way up (by sea) from Sydney and return? Can you leave a comment on our website (bomwatch) with your email. I’d like to discuss further. Rgds David MJ

Bruce of Newcastle
November 22, 2021 1:04 pm

Who cares anyway? Coral grows faster than 36 mm per decade.

And the Dutch can tell you about how to cope with flood-prone land. A man with a spoon could build a dike faster than 3.6 mm/year.

These sea level Chicken Littles are amazing.

spangled drongo
November 22, 2021 5:19 pm

As someone who has been building sea front infrastructure on that same coastline to AHD data [walls, jetties etc] since the 1940s and who checks those that are the best benchmarks at the HATs each year, I have yet to find one example that has shown any sea level rise over 75 years when corrected for barometric pressure.

Many show a slight fall.

November 24, 2021 8:08 pm

2 minutes of math shows that the rate of sea level rise required to meet the theories/models for 2030 let alone 2100 (1 to 1.2 meters ) are ridiculous and just cannot happen , there just ain’t enough energy there to manage even a quarter of it . So why are these people putting this nonsense out ? Unfortunately most people don’t have the sense or drive to do the 2 minutes of math required so just suck it all up and follow the leader .
So why are these people doing this when we know they are capable of the math , hell even a 10 year old could be shown in about 10 minutes or less ,why ?
To keep the panic going which will drive the global carbon tax that these people want to implement on us all , specially the highly successful and wealthy countries . The CT is a stupendous cash cow for these people who are salivating at the thought of managing it , in the multi Trillions per annum . !
Like the ridiculous claim that Biden and other world leaders are claiming that climate change is the biggest threat to the world of all the “problems” facing the world . Baloney ! they have been going on now for 30 years at least about how the world will be destroyed by global warming and a 100 damaging effects by it and what really has happened that is dangerous or life-threatening that can be directly attributed to Global warming or climate change ? Nothing !

More tornadoes . Nope Less!
More hurricanes, typhoons . Nope Less!
More storms etc . Nope
Less snow , will disappear in many areas . Nope !
Growth of deserts . Nope , Sahara is actually shrinking (greening) substantially .
More wild fires . Nope !
Vast migrations of people from parched areas. Nope !
Antarctica losing ice . Nope , actually gaining land ice substantially .
Antarctica sea ice shrinking . Nope ! Around normal.
Arctic sea ice disappearing in summer. Nope.Ice cover is rising from dip and just under normal .
Greenland melting . Nope .Record growth over the last 2 years . Keeping its own .
Oceans coming less alkaline . Nope . Nonsense !
Oceans increase in temperature . Nope . Overall they are dropping in temperature .
More and higher temperature heat waves . Nope and Nope !
Huge sea level rise. Nope ! Around 1.7mm to 2.5 mm per year worldwide approx. A rate that can easily be adapted to over the time period talked about , 50-100 years .

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