Where Skepticism Meets The Shoreline
On Monday 15th September, Australia’s first Climate Risk Assessment Report was released.
The report’s publication was widely covered across all news publications, however in the process a complex science was reduced to simple arithmetic: Average temperature will increase by x amount, sea levels will rise by y cms, insurance premiums will surge by z dollars.
It makes for easy-to-digest news yet it does nothing to help the layperson understand how climate change might manifest itself. Instead, the issue remains an abstraction to many people - it’s something happening over there, or in the future, or perhaps it’s not even happening at all. Skepticism, after all, has a place in science.
Yet things are happening, some of them very close by, that have me wondering if skepticism has reached its limits.
McCauleys Beach, Thirroul (Stu Nettle)
The northern suburbs of the Illawarra - where I live and surf - is a stretch of coastline that performs well when the swell swings away from the prevailing southerly direction. For whatever geological reason, dullard waves develop glowing new personalities when the swell shifts east, and it’s not just the reefs and points but the beaches too.
Fortunately for me, since the turn of the century our weather has been dominated by La Niña events, which are characterised by weather from the east. Think moist easterly wind, rain that follows the wind, and easterly swells too.
More easterly swells..? That equates to more happy surfers, at least in the Ilawarra, though the same applies to Sydney’s Northern Beaches and any other stretch where southerly Hyde turns into easterly Jekyll.
Yet beyond making surfers smile, when we look at the shifting swell direction in NSW there are bigger forces at play, the drivers of which aren’t entirely clear yet.
An otherwise dull wave doing remarkable things in an east swell (Stu Nettle)
Australia's East Coast has been conditioned to a south swell regime. Over millennia, the coast has been shaped by waves arriving from that direction. From the erosion of rock outcrops to the distribution of loose sand, the coast bears the imprint of a southerly swell bias.
Human occupation on the East Coast has also been shaped by swell direction. Think of all those basalt headlands with wide sandy bays to their north and small towns nestled into the protected lee side: Terrigal, Seal Rocks, Crowdy Head, Laurieton, Crescent Head, Hat Head, South West Rocks, Scotts Head and on it goes.
Not convinced..? Take the window seat on any Sydney-Gold Coast flight and watch as the repetition reveals itself from 30,000 feet.
In NSW, coastal land on the north side of prominent headlands has always been highly prized. It’s protected from southerly energy so the waters are benign, which mixes well with the northerly sun vantage. As coastal towns expanded, new houses settled those sheltered nooks, spreading out on the floodplains or clinging to the ramparts.
Coastal erosion, when it occurred, happened elsewhere - mostly at south-facing beaches exposed to the worst of the weather.
Crescent Head is an exaggerated version of the classic NSW town, with a prominent headland blocking southerly swell and houses nestled into its lee side. In the distance are Hat Head and South West Rocks, both continuig the same pattern.
Ian Goodwin is a longtime surfer from Sydney’s Northern Beaches and is also an Associate Professor at Macquarie University’s Marine Climate Risk Group. Since the 1990s much of Goodwin’s climate change work has included tropical expansion as a recurring theme.
Goodwin’s tropical expansion theory proposes that, as climate change develops, the tropics will expand at a rate of up to 1 degree per decade. If tropical expansion continues, the process will affect many people. For surfers, however, it’ll mean swells of tropical or subtropical origin will become more common.
Read: fewer south swells, more east swells, which sounds familiar.
Goodwin isn’t a surf forecaster, however, he’s a climate scientist who’s spent his career studying the weather, and his theory of tropical expansion, if true, will have a cascading effect as the changing climate disrupts long term patterns - patterns that we thought were permanent.
During the infamous June 2016 swell, backyards at Collaroy fell into the ocean while houses teetered on the precipice. Collaroy, if you look at it on a map, is one of those coasts protected from south swells - Long Reef headland blocks the energy from that direction. Historically, it’s received lower levels of damaging south swell yet it’s vulnerable to less frequent north-east swells, which was the direction of the June 2016 swell.
In the nine years since, Goodwin’s theory has gained more traction - and taken more land. The NSW East Coast has been hit by many more swells from the east and north-east. The result being Collaroy and other places with similar north-east exposure are in a state of near-permanent sand deficit. Stockton, Wamberal, North Entrance, Norah Head.
I’ll also add McCauleys Beach, Thirroul, to that list. It’s the closest beach to my home and has, over the last five years, retreated at a remarkable rate. On any swell and a high tide waves eat into the brown earth at the southern end, while four houses at the northern end watch nervously as the cliff line moves ever closer to their foundations. A fifth house has been protected by an old concrete seawall built on the rock platform, yet during the last east swell the seawall broke and the inland retreat began anew.
Rates of erosion are usually measured on the geological clock - they’re imperceptible to humans - yet at McCauleys Beach erosion is now occurring in real time.
Collaroy Beach in the aftermath of the June 2016 swell (Amanda Hoh)
Though La Niña is currently dominating, it hasn’t always been this way. Historically, El Niño events are more common than La Niña. However, when the timeline is reduced to the last, say, 50 years, and especially the last 25, there’s a large upswing in La Niña frequency, which is raising eyebrows among climate scientists.
As you may have guessed there’s a link between La Niña and Ian Goodwin’s theory of tropical expansion. Both describe a state of less south swells and more east swells. Yet where La Niña is cyclical the tropical expansion theory is permanent.
So which one explains our current state..?
This is an important question. If it’s cyclical then let’s enjoy the good times before it switches to El Niño again. However, if climate change is coming to pass and Goodwin’s theory of tropical expansion keeps developing, then the patterns that we’ve relied on, that we’ve trusted so implicitly we’ve built forever homes in good faith, will be disrupted for good.
Surfers might be happy with a permanent increase in east swells, but such thoughts will offend anyone with vulnerable coastal property. It also doesn’t take much to realise that, if things have changed and we’ve crossed the climate change rubicon, then other changes will follow, and, safe to say, they’ll be more significant than our short-term stoke levels.
(Stu Nettle)
One of those cascading changes may well be a reduction in south-to-north sand flow. The East Australian sand transport system is one of the largest sand transport systems on Earth. Beginning at the Hunter Valley, it ends at K’Gari and feeds all the beaches and points in between.
The sand transport system is driven by the prevailing southerly swell. Though the water in the East Australian Current flows relentlessly to the south, the sand in the swash zone moves to the north, driven by wave energy. Its distribution along the coast is consistent with this flow. Many basalt headlands - particularly in northern NSW - were once islands but became joined to the mainland by centuries of sand deposition.
That pattern doesn’t change during neutral or El Niño years - the ongoing south swells keep sweeping the sand north.
During research, however, Goodwin observed what happens when our climate switches from El Niño to La Niña. The result is reduced flow and a lack of 'connectivity' in the sand transport system, with the most vulnerable stretches being - you guessed it - the northern lee sides of large rocky headlands.
Though El Niño and La Niña events are temporary, they’re a good proxy for how sand transport is affected over a longer time frame. Goodwin says: “South winds and swell are the motor that drives the great conveyor belt of sand, and when the motor stalls...then the sand stops flowing."
For much of the NSW and QLD coast, sand is the buffer between waves and the built environment. When erosion has occurred, it’s been naturally fixed by a fresh load from the sand transport system.
So again, it becomes vital to distinguish if we’re merely in a cycle or something more enduring.
If it’s the latter and once-protected corners are being hit by increased energy and losing their natural protection then the issue will continue until a new equilibrium is found.
Coastal home owners will hope the new equilibrium doesn't settle inside their property line.
McCauleys Beach, Thirroul: Three years ago the white PVC tube released water at the cliff face, now it acts as a marker to lost land (Stu Nettle)
Both El Niño and La Niña have been mentioned many times in this article. El Niño is the phase that got the whole system noticed, firstly by Peruvian fishermen in the 1600s - El Niño translates to ‘little boy’, meaning Jesus, as the conditions would arrive around December - and then last century by scientists who linked El Niño (and later La Niña) to broader ocean changes.
Those scientists discovered temperature differences between the east and west Pacific distinguished El Niño from La Niña. Further study showed the system was a very good predictor of coming weather across the entire Pacific basin. For decades, it’s been relied upon for longer-range forecasts, however this certainty is beginning to break down.
Last spring and summer was considered a neutral year by climate scientists - neither El Niño nor La Niña - yet here in coastal NSW we had a summer akin to La Niña: there was much tropical activity, the Northern Rivers flooded, the swell was persistently out of the east, and lee side erosion got worse. It was La Niña without the label.
Hindsight showed that warmer-than-average sea surface temperatures negated the once-reliable metric. By all previous criteria we were in a neutral phase, yet uniquely warm water offshore threw a fly in the ointment. Warm water equals storms and floods (and swells) regardless of the official line.
In response, climate scientists are having to reinterpret the El Niño/La Niña system. “While the system was accurate when the Earth's climate was stable,” wrote the ABC’s Tom Saunders recently, “in a warming world it is no longer fit for purpose.”
"The old calculation,” continued Saunders, “masks La Niña events and overstates the frequency of El Niño events."
(Stu Nettle)
This re-definition by weather agencies muddies the waters yet more. In the age of doing your own research, climate science is a tough nut to crack. Our entire atmosphere and ocean is interconnected and in ways that are barely visible to trained scientists leave alone the curious individual.
Perhaps the best way to make sense of it all is to examine the domain that you know best: for surfers that means the surf, the sand, your local coast, find out what you can, take in the longview, and then weigh your natural skepticism against those observations.
How you act after reaching a conclusion is a whole other story.
//STU NETTLE
Postscript: While writing this article the house at McCauleys Beach ‘protected’ by the broken seawall went to market. Last Friday it sold at auction for a princely sum, the new buyer betting the house on skepticism.
Comments
Ya lost me with the line “While the system was accurate when the Earth's climate was stable,”
Earth's climate is many things, however, stable is not one of them, nor has it ever been.
It depends on your time frame. Decadal, centural, yes, sometimes even millennial.
Thanks Stu, great read. On the point about permanent, cyclical, timeframes and the like it is hard to gauge. I note it was mentioned that some of the headlands were once separated and later filled with sand. One read of that is we could return to what once existed. Perhaps these events (Nina, Nino, warming, cooling) have been part of natures ebbs and flows forever - perhaps not. Above my pay grade.
He's also quoting the ABC journalist rather than describing the system as stable himself. Also, it is a question of stability within the timeframe of coastal development in the last 100-150 years....
I think they are referring to the Holocene
Depends on your time frame. Humans are very poor at understanding the scale of time beyond their own brief life span.
If there’s one thing that our chunk of rock has over most other chunks of rock floating through this universe, it’s stability.
The sort of stability that allowed humans to evolve, and ensured climate fluctuations were relatively
slow and gentle, is actually extremely rare in the cosmos. Scientific observation tells us that the current climate changes we are starting to see are not slow and gentle.
Understand this and you begin to realise just how special our planet is, and that its stability is not something we want to mess with.
Great article on something we've all wondered about, some with more concern than others.
BTW what was the "princely sum"?
$6.1 million.
I'll take two !
Crazy money.
Would Armagh Parade be a bit more affordable do you know Stu?
It’s inconsequential to the story but the geology of those headlands you mention, bare Seal rocks maybe, none of them are basalt.
Volcanic basalt rock exposed include Kiama - Minnamurra, Kulnura, Ballina to Mtn Warning to Mtn Tamborine to Glasshouse Mtns & Orange, etc.
Volcanic uplift created a lot of mtns & islands like Lord Howe, NZ, Taz, Antarctica, etc.
Old quarries forgotten, bluemetal gravel tracks, roads & highways pave the brave new world
eg. https://www.abc.net.au/news/2023-02-19/kiama-s-blue-diamond-basalt-helpe...
One of your best, Stu. Though I think it's more denial than scepticism. That would involve active observation where a person might change their mind, but I don't see much of that.
Agree on all points, Boxright.
Basalt headlands are pretty much limited to Lennox/Ballina area and Burleigh on east coast
Hard to take someone called 'cartfart' seriously but I think you and the other fella might be right.
Nah, many on the MP
Fingal, Cabarita, Snapper/Dbah
caba headland is not basalt, its sediment from the bottom of the ancient continental shelf, half cooked and uplifted
was the Vic -NSW -Qld great dividing range and coast uplifted by underlying volcanics?
Great read
Just wondering if there is some sort of warming in stratosphere happening at the moment and what if any effect it may have on our weather
This is the time of year it always warms, but a couple of rapid heat spikes and a weakening of the polar vortex looks to possibly bring increased frontal activity to the south-east of the country. We're kind of seeing this now and for the coming fortnight at least.
i am not meaning to be dismissive in any way but the cycles of weather and their effects on sand and surf are not well understood in an intergenerational manner. least of all by this rock licker. i was taught by ian over 30 years ago and have much respect for his work. but i have also lived through what more than three decades of predominantly el nino style weather. Perhaps the last few years have been more la nina typical but does a few years mean we are suddenly shifting to la nina dominant weather? this question appears to me to be the crux of the written piece. i certainly dont claim to know, but there were "epic" surf seasons on the points in the 1970s that could be attributed to la nina style events. these lasted a few years also. maybe in a year or two we will look back at the early 2020s with equal fondness?
Rock licker? Please explain .
Geologist?
Landscape gardener?
You mention if the situation is Cyclical or a permanent change. That is the crux? of the whole debate on climate change. We mostly take the advice of Science and trust it many areas of our lives without question. Yet when it comes to this whole climate debate some people are deciding its not happening. In our energy generation things are moving quick to renewables and for the most part its proving successful. The people in denial are supporting fossil fuel companies, they don't want change because they can't make money out of it. Change is coming, weather, as well as many other things about our lives. Look at the people denying Climate change then look at why they have that position, it's not because they're Scientists.
Then youve got all the data mining, crypto and AI energy consumption looking to exponentially gobble up way more energy than we currently use.
" history is recorded today in Aboriginal oral histories of coastal flooding and migration from this time. As sea level rise squeezed people into a rapidly shrinking landmass, population density rose and in turn may have ushered in a new era of social, technological and economic change in Aboriginal societies.
Sea level rise severed the connections to Tasmania and New Guinea for the final time, reaching a peak about 1-2 metres above modern levels some 8,000 years ago, thereafter stabilising slowly to pre-twentieth century levels.
Climate settled into a pattern broadly similar to present, with the last few thousand years seeing increased intensity of the El Nino-La Nina climate cycles leading to the boom and bust cycles we live with today.
Over the last 10,000 years, Aboriginal populations increased , possibly in the later stages with the help of the recent placental mammal import, the dingo .
When Europeans invaded Sahul’s ancient shores, one blink of an eye ago, there were perhaps more than 1,000,000 people in 250 language groups across the continent.
They had not only survived, but thrived, on the driest inhabited continent on earth for 50,000 years or more. There is so much more to learn.
Reference
https://set.adelaide.edu.au/news/list/2019/04/27/australias-epic-story-a...
After the massive ECL 1974 'storm of the century'..... a NSW Coastal Protection Act (became law in 1979) restricting development on the coast eg. https://localhistory.sutherlandshire.nsw.gov.au/nodes/view/103816
https://legislation.nsw.gov.au/view/html/inforce/2015-06-04/act-1979-013
Ballina Council implemented the NSW law and all new development was set back from the coast & even included pedestrian bridges and tunnels at Angels Bch to enable people to walk to the beach without getting run over or building massive carparks clearing the trees slowly trapping sand along windswept hind dunes....
Wealthy people bought these great coastal blocks of land... for their retirement & or investment.
Some retired people volunteered & invested 30 years to restore the damaged sanddunes to recreate littoral rainforests that existed all on the east coast .... before the UK excon's got outa Ol Sydney town asap for forestry$, cattle grazing$ & $andmining .... demolishing most of the large sand-dunes & rivers all along eastern NSW for the last 100 years.
Some progress can be made on degraded Great Southern Lands to buffer the sequential impacts from climate change... if you can invest your time and energy for the next 30 years.???
https://www.ballinacoastcare.org/ourstory/
Thirroul NSW looks like a lot of beaches & rivers in Oz, especially where Mudroch mining mentality maintains mediacrazy. Ozi cozy lazy, gota prime pozi...oiloioioi
https://dictionary.cambridge.org/dictionary/english/mediocrity
Thanks Stu and the swellnet team for your great articles... its the best surfscription
Further studies
https://epicaustralia.org.au/publications/
Insurance companies have already priced all this in. I'm looking at buying a house and I checked the insurance premium on one, in an area that has never flooded although has the potential for flooding. The premium was $11,000! That's right now. Who knows about the future but if you look at those prediction models, most places north of Sydney with an estuary are predicted to be underwater by 2100.
there's a house down my way that was for sale about a year ago for a good 100-200k cheaper than it ought to have been. it was next to a creek and when we asked for insurance quotes it was 40k/year to insure against floods. almost fell off my chair!
Wow.
Stu and crew do you have access to your historical surf reports? I think it would be very interesting to see how surf rating has changed. I am expecting an increase in good surf report scores for spots that would benefit from the change and a reduction in good scores for places, like surf coast(?), that would lose out. I think its an underrated source of data in this type of discussion. I work as a data scientist and would love to help out with something like this
I think the star ratings are too subjective for serious analysis. For one, they've been written by various people who'll bring their own subjectivity. Yeah, they may be consistent, but if they do the reports for a year or two and then another person takes over then the continuity is questionable.
Also, at times short term conditions come into play. If it's been flat for a month then a three-foot day might rate highly. On the other hand, if it's been six feet for weeks then that same three foot day won't rate the same.
Respectfully disagree stu. The modern data science toolbox is vast and extremely powerful. There are tools and methods for just about anything, including what you raise. In fact, I put it to you that I can detect changes in reporters *from* the data.
It won't take long to inspect the data and get a feel for the possibilities.
I am up for the challenge
I have about 42 years stored in the memory banks ! Plenty of big east swells in the mid to late 80s into early nineties.
Interesting theory about the tropical creep.
Here come the crocks and box jellys sunshine .straddle coolie...
I've kept a surf diary on and off for 35 years. It's amazing how bad people's memories are. Someone will try to tell me that 1990 was an amazing year at the local, and yet when I check out my diary it turns out there were just a couple of really good days that year. Bottom line is people will remember a couple of good swells and forget the three months of rubbish surf.
If you really want an objective measure of historic surf conditions then you're probably gonna need actual wave buoy measurements, coupled with records of the local winds.
That's pretty amazing you kept it up.
And yeah, people's memories are pretty terrible
I kept a surf diary from back when I started surfing. Only problem was that my scale shifted over time. I looked back recently and saw that I had written a day as surfing a beach break at 12 to 15 foot when I was 14 years old haha. Was more likely 4 to 6 but to a grommet it seemed huge. Perception when you're young shifts markedly
I frothed pretty hard when I was a grom, then went through a bit of a jaded period in my twenties and early thirties when I was going to Indo quite a bit. As soon as I had kids it was back to being a frother again. Now at 53 years old I'm getting more excited about 1ft at my local than some of the groms. Possibly because I can see that I might have less surfing ahead of me than behind me. Gotta make every day count now.
Haha that's me too. Frothing out on one footers that peel half decent and as much as I love a good wave, I think I've surfed more rubbish in the last 5 years than the previous 20. Make the most of the years left I say
I like the idea but if most people are like me I can honestly say I’ve never looked at the /10 rating for the day.
Peoples opinion on what is a 9/10 day for example would vary too much.
The current surf reporters idea of an almost perfect day where I live might be nice clean 3 foot waves on a perfect V shaped bank.
Then the next person may prefer 5-6 foot nice offshore waves that the previous reporter might struggle to make a take off on or be too reluctant to go out in due to the extra paddling required or duck diving etc.
It’s an almost irrelevant part of the report imo.
Great point, whoever it is that does the observed surf report here is a bit of an over caller size wize , very enthusiastic but not that reliable with how great it is, 5/10 rating
huh, yeah, never look at it...
Global Insurance companies and the US navy who are better informed and resourced than anyone aren’t in denial. It’s the rate of change and likelihood that human activity is contributing and unanswered questions about what comes next that’s cause for concern.
It’d be a damn shame, and not just for surfers, if the shoreline in NSW and SEQ was significantly denuded of sand. You might not see the effects for a century or you might see it in 10 years the way things are trending.
It’s obvious there’s more rain, warmer water and less south swells on the east coast in the last few years. Nth hemisphere fire season is alarming. Cumulative effects of co2 output to date will take Millenia to reverse.
Northern beaches wins a global big wave award, who would have seen that coming 10 years ago?
Yep, the lack of longshore sand transport this season has been pretty alarming.
Pointbreaks here that haven't broken for over a year- they were denuded before TC Alfred.
Definitely seems to be structural change in the EAC.
yep still no sand movement here either......grim
In Victoria we have always had the odd winter (40 odd year time frame) where all the decent swells were too westerly to hit the Surf Coast, but they have become far more common in the last 10 years. (Sounds like that tropical shift).
I'd be interested if anyone has seen any changes on the west side of Cape Otway with this increase in powerful west swell activity.
Feel the fronts came through quicker , ( used to be slower moving ? ) yet it's been years since I stepped foot in vic.
From someone who has lived in the northern Illawarra for over 50 years it is wise to remove specific place names to avoid the situation of visitors from all over the world curiously crawling over the place to the chagrin of the residents...
Remove place names in this article..?
Ha ha - mysto Mac's. Hardly a spot for the travelling surfer outside of the rare day and with no sand even more so.
Yes, those in the photo bi-lines.
Captions?
A byline - or by-line, never bi-line - is the author's name.
But that's by the by...the captions are fine.
Is climate damage tourism a thing?
McDonalds and free wifi attract many visitors.
Surf, sex &... appears opportunistic if OS time is ltd
Timing.
Yesterday, coastal protection works began at North Entrance. Click to read more and see the photos.
another secret spot exposed.... those full carparks, jetskis, packed line ups, pumps & pipes & utubes are a giveaway...
oh ... maybe that was just south Straddy and the goldenboys exposure after their sponsored ego wwwins
They spent $20M on coastal Crown land last major ECL, NSW Govt contribution $0... non compliant
La Niña is here to stay. Period.
And it's gunna most likely get amplified if anything.
This place is an echo chamber of ignorance.
"raising eyebrows among climate scientists."...
Maybe a few can cast their eye to my comments on your "La Niña Murmurs" article where I outline the mechanistic hijacking and manipulation that's actually driving it....
https://www.swellnet.com/comment/1107877#comment-1107877
Maybe i need add more context and data? I have plenty.
"tropical expansion"
I'll tell ya what's expanding - man's ego and technology in the hands of psychopaths. lol.
"However, if climate change is coming to pass and Goodwin’s theory of tropical expansion keeps developing, then the patterns that we’ve relied on, that we’ve trusted so implicitly we’ve built forever homes in good faith, will be disrupted for good."
Mmmmm kay!
Say goodbye to the homes. I'll take that bet EVERY DAY.
cry.
a little harder.
Appreciate you reporting this out, Stu.
Never value my subscription more than reading pieces like this.
(after all these years I kinda take the foreys for granted, but ofc they deserve a hat-tip too).
Thanks Tim.
‘Change is the only constant’ was what I was always taught about change..
Gondwanaland anyone?
Good read Stu! Has anyone got an EIS for planting dune vegetation on beaches?
Enviromental Impact Satement EIS use to be required for significant impact on threatened species populations from projects like major developments.
https://www.planningportal.nsw.gov.au/major-projects/assessment/state-si...
New South Wales is recreating a Liberal fast tracking development quick investments turnaround process that will avoid the need for a thougher EIS review by specialists... going instead to a well fed planning panel... all to reduce time & costs to major developers and...
increase enviromental inherited social & premanent environmental costs for all the future populations in NSW, Australia
Ignoring this part of the planets well known steady decline in threatened & rare remaining species ... even the fn koala, bandicoots, wombats & wallabies.... oyioyioyi FY $$$MeMeMe
https://www.theguardian.com/world/2024/nov/13/nsw-housing-development-ko...
Gotta admit, I'm no skeptic, yet I feel no politican can save us !
Good story Stu - unsurprisingly, the same is happening in many places, including parts of the W coast of NZ, eroding at up to 1 metre per decade. Jim Hansen and other long-term climate boffins think IPCC sea level rise estimates are on the low side, and if he's right then two metres of sea level rise in the next century is likely. For comparison, around 125,000 years ago sea level was 4-6 metres higher than present, evidenced by fossil coral reefs dated to that Eemian epoch all over. Temperatures and sea level at the time were apparently not related to greenhouse gases, but to orbital cycles. In any case, those paying $$$ for coastal property should enjoy it while it lasts. On sand loss and buildup, Noosa's points are the most clogged with sand I can remember in 60+ years. Council pumps sand to maintain Main Beach, but right around to Tea Tree and Granite are chockers. It's a far cry from the erosion and waves off the 1960s and 70s cyclones, and the then desperate placement of rock walls. But in the decades ahead the relentlessly rising sea will take it all back, including the multi-billion $ real estate of Hastings St and Noosa Sound, as those who bought there scream for compensation. Nancy Cato, in her book The Noosa Story, foretold all this, and the formation of the sand islands of K'gari, Moreton, Straddie etc., noting that Noosa's north shore - Double Island Point will be another such island when the sea breaks through as Tin Can Bay and floods the Noosa River. We will all be long gone when it happens, but my guess is that it is pretty much baked-in at this point, given the positive feedbacks in the climate and ocean-atmosphere systems and our continuing love affair with oil, gas and coal. Oh hang on Albo's got it sorted! As it goes ...
I receive James Hansen's email updates regularly, if he's correct we're in a bit of trouble.
Liberal Govt & Murdoch press paid by coal mining ltd to stop the carbon tax in 2013?
https://en.wikipedia.org/wiki/Carbon_pricing_in_Australia
No change, sugar fix, cheap tricks.
Timor invaded by indo military, ABC journalist shot, nuns raped, local communities fled to the hills, their Timor President phones tapped by Oz intel before the big deal... Same time, ellite private school Oz Foreign minister 'unaware' his personal super scheme had invested in this Woodside Petroleum gas project at this time.... 30years of the cheapest evr LPG gas (25c /l) sold to China by Oz PM 'liberal' J Howard.
Balances their bodgey pork barrel books in marginal areas.
Sold Telstra Govt business to wealthy only
Sold his soul.
Albo may be applying a slow and steady appoach to Oz societies need for evolutionary awareness & ethical adaptation to the brave new world ahead
The west coast beaches of Auckland seem to be having the opposite problem of too much sand.
I only have 25 years to look back on but South Piha is almost un recognisable these days. The ditch/pakiti rock are completely buried and the local boys are launching their boats way round in the cove.
“One of those cascading changes may well be a reduction in north-to-south sand flow. The East Australian sand transport system is one of the largest sand transport systems on Earth. Beginning at the Hunter Valley, it ends at K’Gari and feeds all the beaches and points in between.”
North to south? My brain is on a declining cycle, but shouldn’t that read “south to north”?
“The result being Collaroy and other places with similar north-east exposure are in a state of near-permanent sand deficit. Stockton, Wamberal, North Entrance, Norah Head.”
True of all the above, except Norah Head. It is the exception proving the rule, I suspect.
I have watched this area avidly, and closely, for much of 30 years. There has been changes at Norah Head over the last 5 years, but not lack of sand.
The beach at Cabbage Tree Bay (I’ve always known it as that, Google calls it Norah Head beach) directly north of the lighthouse, has seen a major sand transport TO it over the last 5 years particularly. Beaches further north, Jenny Dixons particularly, were scoured back to bare rock in quite a few of the swell events of that period, but Cabbage Tree Bay saw higher levels of sand often, and now seems to be cycling at higher levels of sand then it used to.
A new wave was created in the area, on very specific conditions that you won’t catch, and I’m not telling. Old reliable bombies now break differently and a whole new storm bar was created just in from The Bull.
Has been fascinating to watch, and every new swell event seems to reveal something I’ve never seen before.
But that stretch has always had a circular rip on some of the breaks making them a bugger to surf when it gets bigger. My theory, untested and untestable, was that a lot of the sand further north was deposited south, closer in to the Bay on what must have been a very much larger circular current.
Who can say reliably. Just observations and a keen mind on what was happening.
Soldiers beach meantime has been scraped, rebuilt, scraped again. The concrete road the clubbies used to take the gear down was undermined and collapsed, I was in the car park when that actually happened. (since re-built, quite well too). The old stairs were washed away, new ones now built and concreted into the rock below. Good job there too, eventually. These scraping events were from the southerly swells though as Soldiers faces well south.
A large ENE swell event overtopped the sand spit between Soldiers southern headland and Pelos and gouged out quite a bit. The whole beach has a much lower profile, evidenced by the 2 metre plus wall of vegetation and sand removal. Gravelly has been mostly as denuded as I have ever seen it, seeming to get very little replenishment even when we had that great build up of east coast sand a few years ago.
Things are changing in human timescales now. Fascinating to watch, scary to consider.
Fascinating BF, would be great to see the changes and then the end results with certain swells/waves in real time.
Have done lots of surfing around N E to the south and the amount of land the sea is reclaiming there each swell event is incredible. That they're trying to save those mansions is also the biggest waste of time and money with most of the protection works ending up in the near shore zone! Disgusting.
Maccas has been losing sand since at least the early 80s.
I first surfed it in 1980 and the drop from the grassed area (then a dirt carpark) to the sand was about 1ft. What's it now, about 4ft?
Stu this article is one of your best, it's thought provoking and evokes the earlier article 'Canaries in the Coal Mine'. The theme of which was that surfers are going to be some of the people who first notice climate change; and this theme was developed in the comments.
Change is happening. We are seeing erosion here. Erosion is noticeable where we focus on our favourite sandbanks, but it's most measurable when human built features start falling into the high tide line. If you look at the wall at TQ back beach, in the last couple of years it's formed cracks and needed bolstering as well. Not so much at Grove, but maybe that's more recent, solid work? The council guys have been replanting the dunes with natives up near the Barwon Heads river mouth and were friendly when I asked about the little plants. Some hope there. Maybe the nature of our beachies with the offshore rock formations and less sand movement, but I'm not seeing major changes in the wave quality?
I am thankful that so much of this coast does not feature development up to the high water mark; most of it is up on the cliffs or hills.
Good thought provoking article. From my piece of coast I really haven't noticed much change in 40 years and east coast beaches in NZ are more wider than I've ever seen. Some local west coast erosion going on up the coast from Raglan at Port Waikato with houses falling into the sea then 30 km north at Piha the beach has never been wider with a huge sand slug of millions of tonnes of sand moving slowly north.
I realistically can't see the world giving up their endless energy demands with new data centres popping up everywhere and with their insatiable power demand. It's all very well to live in an AI world but at what cost? The full lifespan of a wind farm or an electric car with all the mining required for the raw materials is also surely not an answer. Many countries are now quietly shelving their carbon emission targets as they're not going to hit them. The only way to reach them is with huge costs loaded onto the public and hence in a democracy, they become unelectable. We're already paying roughly $200 a week in carbon charges per week per family in NZ for electricity, gas, fuel, flights, extra food costs etc. I don't think we can have everything! Cheap power and groceries, AI for everything and cheap cars and transport costs are not realistic and politics will most likely win the day. It will take great science and excellent leadership and communication skills from any countries leaders to make substantial change. Personally I think adaptation is the viable future and people living inland don't want to pay for rich peoples places on the beachfront. The insurance costs will ultimately solve the issue and retreat becomes the norm. That's unless the sea doesn't actually rise as quick as suggested and the doom merchants and the hockey stick graph from Al Gore in the early 2000s are yet to show in reality against the modelling. Interesting times.
The amount of sand that has been deposited at Piha over the last forty years is amazing. I wonder if there's ever been a study done on it. Where has all that sand come from? Manukau Harbour maybe?
By the way, the rich fools who buy expensive property right on the beach and then expect the public to pay for seawalls to protect them can lick my salty nut sack as far as I'm concerned. I hate that kind of bullshit.
Isn't funding a bit of swings and roundabouts? I mean in Sydney we are constantly funding the development of outer W and NW suburbs - from roads, trains etc (a lot of public transport is run at a loss and funded by the public and I notice the W and NW is getting better transport times, nicer newer trains etc than the E). Much is due to significant population growth. So the people in the E suburbs are paying a lot of tax dollars to prop up the W and NW - yet many complain when funding comes to the E such as for coastal protection. Can argue funding for things every which way (including loose). Inclined to think though that coastal house owners should not expect the protection to be funded - although should be able to fund themselves in a reasonable way. One thing that I am surprised is not mentioned around global warming is the impact of deforestation and the impact of concrete and tar to increased overnight temperatures - against what impact carbon pollution may have. I recall reading somewhere that roads/concrete contribute up to 2 degs increase in overnight temperatures - yet here we are in Australia growing our population at a massive rate and increasing the amount of tar and concrete laid - just a thought rather than opinion.
There’s rumblings that they got the sand mining modelling wrong from down south and the sand is travelling way further than expected, ending up at Piha.
We left Piha in December 2005 (I was still a kid) and I remember surfing in the ditch all of that winter. It’s crazy to go back nowadays and look at South Piha only 20 years later, it’s almost unrecognisable.
Yeah OS we used to travel up from the Waikato to surf the ditch when the west coast was huge. It's just buried under sand now. Hard to see how any of the onshore sand mining had anything to do with it. Would have made less sand, not more. Natural causes I would have thought
Great article Stu! Would also be interesting to look at the sediment supply rate changes too i.e. all the river mouths that play a crucial role in replenishing the sand. Dams and channelisation and mining all can cook the connectivity and lead to reduced replenishment.
All factors of course but the most important thing that is effecting our beaches and coastline is that shorelines no longer accrete sand naturally. Sand is being washed off our beaches along with our sand banks with backwash receding from steep shorelines, something that wasn't planned. Steep sided dunes from vegetation planted too close to the ocean over the last 30-40 years has made erosion the dominant process, except on unplanted beaches like Bondi Beach and other natural beaches where low flat beach profiles allow accretion. The Coastal Dune Management Manual. Page 43: "Dimensions (of dunes) may be constrained by the location of structures such as buildings, car parks or roads. This problem is common in urban areas where it is often only possible to reconstruct the seaward face of the foredune." Yep a steep sided seaward face where sand can't accrete. Then there's Page 44: "An adequate beach berm width must be maintained to permit normal coastal processes, especially at elevated high water levels during storms." There's not one Coastal Process on Cronulla Beach that is the same since dune vegetation changed the beach profile from flat and wide to steep and narrow. Most coastal processes don't even exist there now except erosion on the beach and in the water. Another quote I don't have the page for, "If vegetation is successful in locking up sand in one embayment there may be unintended erosion in the next embayment." Were talking millions upon millions of cubic metres of sand here with not one bit of a clue of the results of putting pretty little seedlings on our beaches and letting them go their merry way. Books have been written on stabilisation and biodiversity but not a word on how mass planted vegetation affects coastal process. If anyone finds one I'd like to see it.
Possibly Lukey, but there are relatively few dams on the major rivers on the east coast and in the last few years there have been numerous massive flood events with significant upstream bank erosion occurring in each event, so sediment supply rates from the rivers on the north coast at least may have even increased in recent years.
I’m curious what proportion of sand being transported up the coast is relatively recent alluvial origin and what is older reworked marine sand deposits.
Most of it is older deposits from my understanding.
But there would have been massive sediment outflows from the northern rivers over the last 5 years.
The most recent example of sand erosion we've seen is at Yeppoon, Rosslyn retaining wall/road around the headland and stone wall/boat harbour. Just more man made crap with bad consequences.
As I posted many years ago, it isn't 'climate change' it is 'extreme climate' as all those great surf pics show, storm swells.
Since then we bought a home 0.8 meters above high tide, not really clever. Time for a tree change.
There is no place for scepticism, which can be replaced with scientific method, taking photos, etc, asking knowledgeable people and believing peer reviewed information.
Follow the money, who is making $$$ from climate change ? The coal and oil, gas, petrochemical industries, who had their own research back in the 70's that the damage was starting and would increase. That's over half a century or two generations sitting on our hands.
Who is steering our government to make poor decisions for our future ? Recently Woodside. Why doesn't the surf community get more vocal about the big issues which will effect our grandchildren ?
After 50 years of not voting, I have at last been shaken from my slumber and am now voting and starting to take action for our futures.
A vein of basalt runs from Collie south down to the coast at Black point east of Augusta . Ancient volcanic action even in WA !
Just go surfing
The Saharan desert used to be a lush rain forest.
The coastlines around the world have changed since the dawn of time.
There are 3 billion people in China and India impacting the environment more than the entire so called Western population will ever do, yet the West are the only people who seem to be concerned.
Or is it just that our scientists get paid to prepare reports that favour the virtue signalling rich people with beachfront properties.