The long running saga of the Christchurch city council’s attempt to introduce new planning guidelines for suburbs threatened by flooding and sea level rise has reached a new level of absurdity. A five person panel appointed to conduct a second peer review of a key report on coastal hazards includes two high-profile climate deniers with strong links to extreme right wing climate propaganda groups. From Friday’s Press:
The list of experts approved by the council included New South Wales University coastal engineer Dr Ron Cox, Canterbury University coastal studies senior lecturer Dr Deirdre Hart, Waikato University earth sciences senior lecturer Dr Willem de Lange, retired Environment Court judge Shonagh Kenderdine and statistician Dr Keston (sic) Green, of South Australia University business school.
Cox, Hart and Kenderdine are all highly respected experts in the field. However, Kesten Green and Willem de Lange both have long histories of working with and for groups seeking to delay action on climate change. It appears they have been added to the panel as a sop to deniers amongst the coastal residents campaigning against the council’s proposals.
De Lange is a coastal processes expert, but his shoddy work for the Heartland Institute-funded Not The IPCC report and UK climate denial campaigners the GWPF makes it highly unlikely that his contribution will amount to more than knee-jerk rejection of projections of future sea level rise. He’s on record, for instance, suggesting that there’s a 0% chance of one metre of sea level rise by 2100.
But the real surprise is the inclusion of Green, a lecturer in business studies at the University of South Australia’s business school. Green has no detectable expertise in coastal processes or planning, but like de Lange has a long track record of climate denial. He is listed by the Heartland Institute as one of its climate “experts”, and has published a number of papers with notorious fossil fuel-funded scientist for hire Willie Soon. One of the latter — a 2009 “audit” of polar bear population forecasts — was so flawed that it attracted one of the most outspoken rebuttals in the scientific literature.
In this rejoinder, we have shown AGS [Armstrong, Green and Soon] to be scientifically wrong or misleading on every major point in their attempt to establish doubt about those reports.
The panel was put together by consultants GHD at the request of the council, The Press reported.
GHD consulted with the public, including the Christchurch Coastal Residents United (CCRU), to come up with the list of experts and key questions it wanted the panel to answer.
The peer review panel would be asked to consider if the Tonkin and Taylor report represented good science, if the findings were still relevant and whether or not the report and its findings should inform planning for future land use decisions.
While a case for de Lange’s inclusion on the panel can be made on the grounds that he has relevant expertise and would be “friendly” to the views of the deniers active in the CCRU, it’s hard to fathom why GHD should put Green forward. It’s even harder to understand why the council were prepared to allow his appointment to stand. Did nobody at the council or GHD do due diligence on Green’s expertise?
Why are the ratepayers of Christchurch being required to pay for the opinions of an Aussie business lecturer who knows nothing about sea level rise or planning issues?
If this fiasco has one saving grace, it’s the presence of Kenderdine, Cox and Hart on the panel. Shonagh Kenderdine is a former Environment Court judge who presided over the creation of the New Zealand Coastal Policy Statement. It’s unlikely that she will tolerate too much nonsense from de Lange and Green.
I also have considerable sympathy for mayor Lianne Dalziel and the council. They are having to make policy in the absence of any guidance or assistance from central government. The Key government’s pathetic abdication of its responsibility to act in all areas of climate policy leaves councils working piecemeal, creates unnecessary expense for ratepayers, and makes hugely important long-term decisions vulnerable to the distorting influence of a few vocal cranks.
I grieve for Christchurch, with Cathedral Sq barely 4m above sea level and the high tide mark on the Avon above the Barbados St bridge, the potential of 20-100m SLR makes the whole rebuild a fiasco.
The only mildly redeeming thought is the prat who built an $8M home right on the estuary at Redcliffs. Except I’m likely to wind up helping to pay for his insurance claim unless IAG specifically exclude flooding.
So NZ does not have enough climate change deniers, and one has to be imported from Aus? Credit to NZ.
Jokes aside, it does look like council wants the perception of “balance”.
At the end of the day it matters not the machinations and the determinations this panel put forward for inclusion in `The master plan`. SLR as part of climate change is pretty much locked in. It`s not a matter of `if` just how much how soon. So by all means have your talk fest but know that the planet and the physics that are now locked in will prevail regardless.
I agree ElToro. It is increasingly becoming a game of Find-a-Mug in relation to properties in the coastal zones, and beside river floodplains, as sea level rise and the intensity and frequency of precipitation events increase, as predicted.
So it becomes a game of musical chairs for property owners – will they be able to find a buyer when the insurance companies and banks pull the plug and the music stops? Its not as tho people have not had sufficient warning or the opportunity to educate themselves on matters of due diligence in relation to properties which may be at risk.
I wonder when land agents start putting disclaimers in their contracts which attempt to absolve them from liability if a property turns out to be unsaleable due to ‘external forces’ which they neglected to mention in the Sale Purchase Agreement? That’s without putting their sale fees at risk, of course!
The red stains on the map of coastal Christchurch and Waimakariri District will not be erased by this recent decision to drop the plan change. Both council and land agents will have a duty to report what they know about the properties. This planning process mess merely increases the doubt and uncertainty for buyer and seller, leading to a patchwork of outcomes which can benefit no-one.
The economic impacts of some sensible response to these forseen risks, of course, are enormous. Once one council successfully imposes and stands by such rules (particularly those prohibiting the issue of building permits on sites where it is unlikely that a 50-year building life can be realised) then others will quickly follow.
We have seen how the government deals with a probability-based risk like further earthquakes. It defines a zone of unacceptable risk and demolishes the buildings in the zone. In this case we are not dealing with a ‘probability’ of say another serious earthquake, we are dealing with the an event which is certain to occur, with a difficult to define timeframe (within certain bounds). Should zoning and demolition be the response to this eventuality? Why not?
Once the legislative and planning ball starts rolling, then engineers will start advising their councils that low-lying infrastructure such as sewage treatment and disposal works will be inundated very early on, rendering all tributary properties unsuitable for habitation due to lack of the necessary public health utilities. In Canterbury the effect of the progressive inundation of the Bromley sewage treatment facility will impose this public health issue on sites as far upslope as Templeton, and beyond, and everything in between.
Similarly important water supply points and aquifers will be affected by saltwater intrusion and the inundation of pumping stations long before the properties served by those supplies get wet feet.
Complex, predictable, unstoppable and really really sad.
Now we understand Andy’s comment about “peer review” a while back.
It would appear from the coastal residents Facebook page that Andy was deeply involved in the selection of the panel. Perhaps he’d care to comment on the process. Who did the CCRU propose? Were they guaranteed a certain “balance” on the panel?
A number of names were put forward. The community reference group, of which I was a part, consisted of a number of people from different communities, many with different angles on the climate issue.
The members of the group were pretty transparent on where they stood and what positions various proposed peer reviewers might take.
The Christchurch coastal hazards issue is a model of how not to do it. This was a point brought up at the recent sea level rise conference in Auckland.
We should remember that whatever outcome this peer review takes, the Independent Hearings Panel has the power to intervene and make recommendations. They have already requested re-mapping of flood areas based on 0, 0.5 and 1.0m sea level scenarios. This is a useful exercise in separating the current flood zones, many a result of earthquake subsidence, from potential climate impacts
As it happens, the panel hasn’t been finalised. There are still question marks over whether some can do it, and so the final makeup may well change
Thanks Andy. What were the names you put forward?
How on earth did Green get on the list? If it was at your suggestion, who pointed you at him? He’s hardly top of any list of statistical experts – especially when there are much more credentialed NZ-based people on the short list!
I can’t remember all the names. I’ll let you know if the panel makeup changes
Fib! How many names were on the panel? Can’t remember? The dog eat your homework? 😉
Seriously you will have to be more convincing….
Btw: you “memoan” on that facebook page above mentioned that “Unfortunately, no one is interested in data and facts anymore.”…
What total hogwash from you once again. Obviously, data and facts are paramount for our climate change and sea SLR predictions and the science institutes devoting their energy on that topic will be driven by just that: data and facts.
If their findings and predictions do not match with what you wish they would report, perhaps first question your own methods of interpretation. And you know very well that forecasting a linear SLR trend as Mr. Jowsey suggests on Facebook is entirely unscientific based on what we know about the trend.
http://www.scientificamerican.com/article/new-data-reveal-stunning-acceleration-of-sea-level-rise/
You can watch the video of the GHD presentation to Christchurch City Council which mentions most of the names, here:
http://councillive.ccc.govt.nz/video/6363
Specifically, at 13:45 into the video
You were asked a very specific question: Who suggested Green for this panel? And did you have anything to do at all with that suggestion?
Waiting……
Thomas writes:
“You were asked a very specific question:”
and I am going to give you a very specific answer.
“It is none of your business”
I thought that you were in favour of open and transparent regional planning?
Yes I am in favour of open and transparent planning. I don’t respond to implied threats.
Thomas can take a hike. If Thomas or any other activist wants to get involved with local government in Christchurch, please feel free, Jetstar are cheap, I’m told.
Uh, I guess a nerve was hit with the dental drill….
Andy: It is our collective business to know who is trying to influence political outcomes and why and who is paying for it too! This is what a transparent political process is all about. It may not be convenient for those who like to scheme behind closed doors but if you want to play at the table of democracy you must be prepared to show your cards.
Thomas writes:
Political? I thought this was a scientific peer review. As for who is paying for it, the Christchurch ratepayer.
GHD are releasing a Press Release indicating that they are still in the process of firming up the panel, so the Press were probably a bit hasty in releasing these names.
You can, of course, contact them if you wish further info. Since the community group spent around 8 hours in meetings at their own expense, I don’t think it is incumbent on the volunteers to offer any info
Andy, on occasion we agree: “Political? I thought this was a scientific peer review.”
Indeed, it is a scientific peer review. The more questionable then, that a person such as Green would be suggested to the panel who, as Gareth pointed out above eloquently, has nothing to offer to this process but a politically motivated position of well-documented denial of the very science that expertise would be needed for.
What is political Andy, is the policy that is derived from the advice that the panel will provide. And therefore, the whole process belongs under the scrutiny of the public. Thankfully it is. With the exception at the moment of who suggested Green and why.
Thomas, are you sure that catastrophic climate change/sea level rise is 100% certain in 100 years, and that we need to stop building in coastal suburbs?
If not, then maybe someone with experience in stats would be of use?
I am reasonably certain that New Zealand is well endowed with good statisticians. The question is why pick one who is a quack denialist?
Also to predict future trends is not as simple as looking at the trends of the past 100 years, particularly as certain tipping points get crossed, e.g. loss of Arctic albedo, methane releases from numerous reservoirs. As I understand it these effects may not be picked up from studying the trends of the past 100 years.
Andy: two points. Continued sea level rise is 100% certain until the oceans and ice sheets come into equilibrium with atmospheric CO2 levels. I’ve pointed out many times that 400ppm CO2 = 20 meters of SLR (from paleo data, not modelling). If we can get CO2 down to 300ppm, we’re still likely to see 5-6 meters (see Eemian data). The only question is how long it will take the system to get there.
So the risk associated with coastal development comes down to a question of cost and expected lifetime. You want to build an extension to your home? Shouldn’t be an issue. Want to build a new sewage system to last 100+ years? Then you need to build with plenty of contingency for SLR.
We also need a system to manage retreat away from coastlines as they become vulnerable. Doing that piecemeal as local authorities are at the moment is bound to make everything much more complex and expensive than necessary.
The lack of national guidance on the whole issue leaves it open to people like yourself to get involved. Your views on climate change and sea level rise are so far out of the mainstream of expert understanding that you will complicate the process even more than it need be.
Well, I do agree on the national guidance issue, and there are some moves to make that happen. As for infrastructure, sure that makes sense. Christchurch is doing little to improve infrastructure in the East. The Bromley sewage works are in the East, as is the large dump in Bottle Lake forest.
Yet, the council issues building consents for $1million+ properties by the coast as long as they meet floor height standards. However, others are being told that vacant land has no value as building is not permitted.
They also promote the east via programmes such as Regenerate Christchurch
It is a dog’s breakfast of inconsistent policies, unnecessary red-tape and confusion. Even the Parliamentary Commissioner for the Environment’s office can’t understand ChCh policy
None of this had to happen if they didn’t try to force the coastal policy under CERA legislation. This wasn’t the council’s fault as it came from higher up the command chain
At the recent SLR conference in Auckland, the ChCh policy was held up as an example of how not to do it.
GHD have been highly professional in their approach at engaging the community in determining the terms of reference for the peer review. Anyone could have joined the group, and at least two of the group could probably be described as “climate activists”, so the idea that it was infested with “deniers” simply isn’t true.
We just wanted to get a fair outcome for coastal residents, and will continue to work towards that.
Firstly regarding the panel. The article above notes that we have a five person panel with two climate sceptics. Given various polls show 90 – 97% of climate scientists think we are altering the climate, a more appropriate balance for the panel would be one climate sceptic maximum. This would be “fairer” as Andy seems so concerned about “fairness”.
I dont see what a specialist statistician would really add. Predictions are more a matter for scientists and they are trained in statistics.
However the Christchurch process does seem a bit haphazard. My understanding is people building in low lying areas are to be told of risks of sea level rise and also what if any protection will be offered by councils. In terms of sea level rise this will be a best estimate or probability. I cant see a problem with any of this. People need information and then they can make their own decisions.
So what is holding the process back? I wonder if its the following: The IPCC have covered the most likely projections on sea level rise, however NZ is complicated because sea level rise appears to be counter balanced by significant geological uplift and subsidence. Predicting that is challenging. Does anyone know if this is an issue confounding the process?
However we have to make the best prediction possible, and attach a level of certainty, and this needs to be on LIM’s. This is the basic minimum requirement surely especially if you want to build a new home in an existing low lying area.
Given councils build infrastructure like roads that are supposed to last 100 years plus, this raises the question of whether they develop future low lying areas or not. Surely some areas are going to have to be off limits where sea level rise could be very significant. You dont want to be abandoning areas after relatively short periods when infrastructure still has plenty of life left in it.
The community reference group had a wide range of expertise (or lack of), political views and attitudes towards climate change. We had one academic with a PhD in paleoclimate, for example.
I don’t wish to name people here because I think it would be inappropriate to do so in a public forum without their permission.
Statistics are important, in the context of the RMA, because they use terms such as “likely” and “possible”.
As it happens, the final makeup of the panel is up in the air, hoping to be finalised in the coming week. There are a number of reasons that panel members might change. These include availability, cost, and self-admitted conflicts of interest
It has been my often painful experience to find that even one person on a committee with a hidden agenda or who does not discuss an issue in good faith can incapacitate that committee. There is a tendancy for people who attemp good faith contribution to resign or to require the removal of the obstructors.
Then there is the saying about “lies, damned lies, and statistics” which applies to people who use statistics to engage in deception. I’ve been aware of many instances where actual observations are required to ground statistics in useful reality as is demonstrated so often by Tamino in ‘Open Mind’
Fake balance. That panel will be so dysfunctional. Many people do not realise that we live what is probably the most erosion prone country in the world. The number of years that it takes the sea level to rise one metre is almost irrelevant, it is going to happen so we should plan for it now.
For those interested, Petone in Lower Hutt is undertaking a spatial planning exercise with climate related SLR in mind in an effort to keep ahead of the game. Its called P2040 (Petone 2040) and involves local residents. Tsunami, liquefaction and SLR have been placed in a combined map showing high, medium and low hazard areas. You can see the key hazard maps at this link: https://dl.dropboxusercontent.com/u/66221494/Preliminary%20Petone%20Spatial%20Plan_Final%20Report_28.04.16%20hazard%20extract.pdf
Hi Tom,
That URL doesn’t work for me, can you try a different one (may shorten the name of the pdf first)
I would be quite interested in the Petone report because I think they handled things a lot better up there than down in ChCh
Thanks
My current workplace is in all the “red” categories. But I’ll only be there for at most 2 more years.
AndyS in typical form I see …
For some reason I can open the pdf now. I see that there is no mention of IPCC 100 year projections; just a brief mention of current SLR risk
The events in Sydney over the last days show what is in store when relentless SLR combines with king tides and wild weather…..
Imagine the effects of this sort of storm when the SL is 50cm higher than what it is now….
Already even that much SLR will create enormous new problems. Then imagine 1m, 2m….
If people from the end of the century could write a letter back to our time, what would they say in it….!
I don’t think Andy (and his friends from the denier side) would find much encouragement for their current stance in those letters one can imagine. Quite likely the letters from the future would urge us to take immediate and significant action to curb emissions of GHG and if necessary remove for good those from any positions of power and influence who still deny the science today.
Imagine we could write a letter …
Imagine that we could get a fair peer review.
The council have remodelled the flood maps that shows little or no threat to Southshore from flooding even at 0.5 m SLR
At current trajectories, this will take 300 years to happen, before we need to even think about the problem
There won’t be Sydney like events because we are protected by a large dune bank
Oh Good Grief!! The Southshore sand spit is a “temporary geological feature”, it could disappear overnight even without SLR. I would put too much faith in sand dunes. An example of their fragility was the dune bank that held the Waimak River’s mouth at the Spencerville end of the Brooklands Lagoon prior to the floods in the 50’s. The river punched through that overnight.
The other worry for the sand dunes of Pegasus Bay is their rapid decay. When my Mum was a girl, living at Amberley, Amberley beach was broad and sandy, like Brighton, idea for trawling for fish. They’d get flounders so big they had to be cut in half to fit on their biggest frypan. By the time I visited that beach as a child in the early 50’s it was a gravel beach like Birdlings Flat, the sand had disappeared. A visit to Leithfield Beach a month or so ago showed it in turn is steepening and losing sand rapidly. One possible explanation is that the Waitaki Scheme has created a series of settling ponds so a significant proportion of the sand being brought down the Canterbury rivers isn’t making it around the Peninsular.
The other worry we can take from the NSW events is the sheer ferocity of the storm. We can’t claim a direct link between that and climate change but it is exactly what we can expect from a more energetic atmosphere.
If you think the spit will disappear “overnight” then this contradicts the science from
the council
If you would like to explain to the residents who have spent over one million dollars, in some cases, that their properties are completely worthless, please feel free to attend any of the local residents association meetings.I’m sure your wisdom will be well received
Of course, Christchurch could also disappear “overnight”, especially if the Alpine Fault ruptures and the Waimak redirects though the centre of ChCh, as has been postulated
I’m sure we should abandon the entire city based on that risk alone
If you think the spit will disappear “overnight” then this contradicts the science from the council.
I’ve no idea why the council or its advisors think that way. ANY coastal property is at risk, as we are seeing right around the world these days.
If you would like to explain to the residents who have spent over one million dollars, in some cases, that their properties are completely worthless, please feel free to attend any of the local residents association meetings.I’m sure your wisdom will be well received
What would be the point? Anyone buying property should do due diligence. I made sure our property in Papanui was well above any Waimak flood channels, although because it was purchased during the 70’s I was unaware of the potential risks of serious SLR even in the western suburbs, even if they aren’t likely for a century or so.
Of course, Christchurch could also disappear “overnight”, especially if the Alpine Fault ruptures and the Waimak redirects though the centre of ChCh, as has been postulated
I supposed you fondly imagine the stop banks on the southern side of the river are the same height or lower than the northern bank?? From my own observations, the river bed is higher than the land outside the stop banks so the challenge, should you chose to accept it, is to consider how to get a river to go back into its old bed when it has found a new, lower level to flow in. Probably to the north as the airport and city are considerably more valuable than Kaiapoi.
Sorry if that thought pops some bubbles, but you can’t argue with physics.
Andy said: “0.5 m SLR….. At current trajectories, this will take 300 years to happen….”
Sorry Andy, these are not the current projections based on the scientific evidence. This is your own simplistic linear model which is complete nonsense! Do you really want to be seen and remembered for pinning your hopes on something that is clearly wrong?
https://www.washingtonpost.com/news/energy-environment/wp/2016/03/30/antarctic-loss-could-double-expected-sea-level-rise-by-2100-scientists-say/
“This is your own simplistic linear model which is complete nonsense! ”
It is not a simplistic linear model. It is what is commonly known as “reality”
https://en.wikipedia.org/wiki/Reality
i.e what is happening, right now.
We don’t know what will happen tomorrow, but the current trajectory is not accelerating, as we see in the tide gauge records.
Andy said: “We don’t know what will happen tomorrow, but the current trajectory is not accelerating, as we see in the tide gauge records.”
Nonsense again Andy.
a) the current trajectory is accelerating:
https://robertscribbler.files.wordpress.com/2015/05/hansen-sea-level-rise.png
b) we know a lot already about the factors that are contributing to the observed acceleration of SLR, certainly enough to make well-educated predictions about the trend going forward. And there point to a reasonable range of expectations of SLR.
Lately, these have been revised upwards.
So Andy, for somebody trying to prevent our councils in the country to take precautionary measures you are rather ill-informed about the whole matter and continue to be caught out spouting nonsense. You offer a “great advice” no doubt to land owners affected….
🙄
Even a 30cm rise in sea level will have a devastating effect on dunes and this has been known for years.
The Bruun Rule explained
So you think that old survey data and tide gauges mean that you can extrapolate what happened in the recent past into the future? I thought as a “mathematician” you at least would know the dangers of extrapolation and not taking new evidence into account – such as the instability of the West Antarctic Ice sheet
The Bruun rule is used extensively in the Tonkin and Taylor report. Interactions between rising seas, wave actions, high tides etc are the issues that should be addressed in the peer review.
Nevertheless, when you have a rapidly accreting coastline, and about 100 metres of dunes between you and the sea, there is quite a bit of protection, much more so than the Sydney residents
I would also like to add that I wasn’t extrapolating anything. Making the statement “at current trends” doesn’t mean these trends will continue. I never made that claim
” I never made that claim”…. Lier, Pants on Fire..!
Above you offered the calculation that 0.5m SLR would take 300 years to happen. This is only possible if AVERAGE trends of 1.7mm/y over the last century were to continue in a linear fashion. So yes, you very much made that claim by implying a 300 year window for 0.5m SLR!
But already the current trend is about 3.2mm/y…..
Andy, let’s face it, you are either clueless in Gaga Land or you are a deliberate misinformer. The latter is the only reasonable conclusion any right minded person can come to when considering your record of “opinions” held over the years…..
Thomas,
The local NZ sea level rise trend via tide gauge records is not accelerating (Hannah et al, Otago, MfE, Tonkin and Taylor)
The claim that SLR has accelerated to 3.2 mm/year is spurious because you are comparing satellite data with tide gauge data. Neither individually demonstrates acceleration
Church and White have published two papers, to my knowledge, that claim a statistically significant acceleration on global sea levels. (C&W 2006 and C&W 2011)
C&W 2006 claims that
I have calculated the numbers based on their claims and can’t match the TAR values they suggest. Maybe someone can check for me.
Then, later C&W 2011 claim a statistically significant acceleration of 0.009 ± 0.003 mm year−2
http://link.springer.com/article/10.1007/s10712-011-9119-1
Note that this is less than the 2006 number.
These rates of acceleration give an addition SLR of less than 5cm over the secular trend of 17cm per century, according to my calculations, which I am happy to be corrected on, of course
23cm of SLR is a lot less than the one metre being quoted by our council
If that isn’t extrapolation I don’t know what is!
Dictionary:
“Extrapolate: Mathematics extend (a graph, curve, or range of values) by inferring unknown values from trends in the known data.”
Yes and I’m sure the people of St Clair’s Dunedin held the same view a few years back too.
Re St Clair’s: it would be a classic case of what is wrong with sea walls. Just to ensure it would go wrong they reclaimed about 30 metres. When seas meet sea walls scour ensures they get undermined. As a result even bigger waves get to crash into them more often. I was interested to note that past failed sea walls emerged from the sand during the storm that just hit Sydney. Many failed farmers’ sea walls I have noted on the south side of the Manukau Harbour.
The sea can be contained by a gently shelving beach (backed if possible by dunes) that dissipates energy gradually via a series of breakers.
Alternatively an offshore reef or sand bar can do the same. People want permanent solutions – I’m not sure there are any.
I lived a bit at Ohope (wide shelving beach) and with my father operated a launch out of Ohiwa Harbour with a constantly changing bar. Every time we went out we first studied the bar from the hill just before descent into Ohope. In normal conditions the bar would form a long curving arc from the sandspit fronting the harbour, east toward Ohope. We would have to motor some distance broadside to the seas to get round the end. Every so often the tide would break through the bar toward the western end which we would then use and the whole cycle would begin again. Eventually we decided to use the Whakatane harbour. Back then only one old squatter live on the Ohiwa Sand Spit. Last time I visited most of the spit had been built up – obviously few took note of the parable about those who built on sand. Ohiwa is yet another place that could be wiped out by a large storm exacerbated by sea level rise.
Noel: “The sea can be contained by a gently shelving beach (backed if possible by dunes) that dissipates energy gradually via a series of breakers.
Alternatively an offshore reef or sand bar can do the same. People want permanent solutions – I’m not sure there are any.”
There is one semi-permanent solution. Undersea dunes created by artificial seaweed. Sheets of (recycled?) plastic rolled & welded along the long side to form a sausage, the remainder slit to form long tapes or fronds extending out from the sausage which is filled with sand before being laid on the sea floor parallel to the beach. As the plastic fronds float they tend to trap drifting sand which accumulates to form dunes underwater when hundreds of the tubes are laid along the beach.
Incoming waves trip up over the dunes dissipating much of their energy before they hit the beach proper.
If a storm strips the top off the dunes, the fronds are exposed and resume trapping sand until the dunes are restored.
With careful planning the dunes can create ideal surfing conditions at minimal expense and no on-going expenditure.
Sorry, my browser began to crash before I got through
the corrections. The Ohiwa bar curves east toward Opotiki, not Ohope.
Actually Noel I wasn’t referring to the sea wall at the western end of the beach – which as you note is a travesty in itself. The dunes further east are large and “protect” the land behind – but they are eroding as any casual inspection will show, and as seas get higher and waves get stronger the erosion will continue.
As for Ohope – I have commented here on similar lines. It again is a disaster waiting to happen. The last severe storm saw many houses inundated and storm waters had no where to go. Walking on the top of the dune one can easily see that the houses are almost at sea level if not below. Early morning on a high tide the stench of trapped sewage and sluggish storm water is palpable!
Kiwiiano that sounds like a sensible solution – but I have one query. Where does the trapped sand in the off-shore dune come from? According to the Bruun Rule the sand eroded from the onshore dunes raises the sea bed along the shore. So is it in fact protecting the land dune?
Macro: it may depend on the supplies of sand to any particular beach. In the Dunedin context I assume the undersea dunes would capture sand being scoured off the land dunes. Once they are established they protect the land dunes from further decay by causing incoming waves to break well before they reach the beach dissipating much of their energy.
If there is an external source of sand for Dunedin beaches they would capture any drifting by. There must be some coming down the Taieri River and there’s no shortage at Aramoana.
The only fish-hook I can envisage is that being made of plastic they would eventually make a tiny contribution to the amount of plastic fragments floating in the oceans. But so do sandbags and that is demonstrably a futile effort.
“As the plastic fronds float they tend to trap drifting sand which accumulates to form dunes underwater when hundreds of the tubes are laid along the beach.”
It’s a nice idea except I doubted the ability of non-self-repairing, non-regrowing plastic fronds to hold up like kelp, so I searched for an example – the UN listed a trial in the Carribean. The fronds were all gone except for some fragments by 8 months, and little sand accretion had occured. Has any advance been made on this?
Local sea level rise is a tricky one. In some cases local sea level may fall due to gravity effects caused by ice sheet melt.
So the council has a complex situation to base policy on.
The current around 3.4mm per year global average sea level will definitely continue, as far as I understand it is half thermal expansion and half ice sheet melt. Thermal expansion is guaranteed to increase because of global warming. Ice sheet melt is likely to continue and accelerate. There is a small chance that ice sheet melt will slow down or even stop/reverse in the near future, probably a very small chance.
The gravity-related effects on SLR are said to be evident for up to 2000 km from Greenland, and I imagine (because of its somewhat greater mass, for a bit more re the Antarctic. That means the effect (a lowering sea level trend among the rise due to melt) will possibly be observed around the south of NZ, but not much (I imagine) around Christchurch.
Also this effect will also only kick in long after we have suffered the worst effects, as a mere 10% melt of Antarctic and Greenland will raise sea levels by about 6 to 7 metres. That rise will trash coastal development world wide (including Canterbury, Kapiti et al), but the comparatively minor mass loss will not give much relief due to the gravity effect. We will be way past caring about subtle technical mitigations by then.
Following up on Thomas’ observation about Sydney, damage and loss from actions of the sea, such as coastal erosion, king tides, or storm surge is not covered by the majority of Australian insurance companies. There are some exceptions, but they’re driven by economics not ideology. They know the seas are rising, and they won’t accept the economic risk. Consequently, many coastal property owners are now in for a nasty surprise.
The situation with insurance companies here in NZ was being discussed when I was doing postgraduate research on the vulnerability of the Pegasus Bay coastline to rising seal levels. Following the earthquakes, insurance companies have become even more risk averse. Regardless of the makeup or outcome of the CCC’s review panel, or what people chose to believe or disbelieve, if your property is near the ocean, it would pay your to check your insurance policy.
I gather they call this now an “Act of Nature” rather than an “Act of God”. Maybe they think it is more difficult to sue Nature than to sue God
I agree check your insurance policy if you are building in a low lying area.
Hopefully Christchurch get their act together and resolve appropriate warnings to put on LIMs etc.
However maybe theres an element of social darwinism. If people are so stupid that they ignore climate change or think its a scam, they get what they deserve. Of course sadly the rest of society will inevitably pick up some of the costs of their stupidity, one way or another.
We could be locking in 20 metres of sea level rise, from what I have read although obviously over a period of several centuries. NZ cannot escape this regardless of local conditions. And sand dunes will be no protection.
Sea level rise will lock humanity into a process of building and retreat, rebuilding and more retreat, repeating over and over. Wondering where it will end.
Returning to the nomadism of pre-civilisation? and the next great flood? Many civilisations have a great flood legend – not just the biblical Noah story. As these legends all come from stories hand down over millennia by word of mouth it would seem that they originate in the past warming leading from the last ice age to the present.
But whether humanity will survive the forthcoming continued warming is another matter – we are well into the 6th Extinction.
Check out if you can “The Tigris Expedition” by Thor Heyerdahl (1980) A reed boat, three civilisations trading with each other, the Euphrates, linked flood myths and archaeology – fascinating read. Not Ice age though.
“If people are so stupid that they ignore climate change or think its a scam, they get what they deserve.”
The problem is that we do not yet know the magnitude of the change, if any. Populations will not be motivated by policies. Unless the actual sea actually invades the actual living room people will not be motivated to move. You call that stupid. I call it pragmatic. Would Al Gore have a fire sale of his seaside Florida mansions?
As mentioned above by others, the cold calculating insurance companies will be the first to leave. That restricts bank lending and that will restrict property sustainability for many. Some might snap up bargain coastal items to enjoy on their private savings while the sea stays away. But society as such will be learning by the way of the bank managers call and the refusal of renewal of insurance how things really are….
I think you’ll find that Al Gore’s Florida beach front property is actually an ocean view property in California. There’s a big difference between beach front and ocean view.
NigelJ”Sea level rise will lock humanity into a process of building and retreat, rebuilding and more retreat, repeating over and over. Wondering where it will end.”
The sensible ones will be retreating once, to well above the 100m contour that should be above even an eventual worst-case scenario. Probably everyone who can will too because you may struggle to get insurance and thus any sort of loan on a vulnerable property irrespective of what the reports may suggest. Insurance Underwriters tend to be a bit more steely-eyed than Politicians, Economists and Property Developers. It won’t stop people building or buying in those areas of course but I’d recommend checking Genesis Ch 6-9 for details of a suitable flood-resistant dwelling.
Here is an article in the NBR from the ‘expert’ that Andy wants in the panel.
I fully support academic independence but I struggle to see how someone like de Lange can have tenure when his views are so divorced from established science. There is a complete disregard of the many papers that show that sea level rise is accelerating. They are turkeys at Thanksgiving, because there is no prior evidence they assume it can’t happen. Future models of sea level rise are based upon what we believe is happening to ocean temperature and ice melt, but the authors categorically reject them as false, even though it is outside of their area of expertise.
Oh yes, De Lange and Leyland, even now publishing their opinions together hand in hand in the National Business Review. Goodness, do the editors of the NBR have no fact-checking department? Have they no recollection of the follies of serial nonsense teller Leyland who, with his compatriots of the “Climate Science Denial Education Trust” still owes the taxpayer a stately sum of money for his wicket law case against NIWA? And De Lange, a disgrace for his employer one must assume…
Academic Freedom is all nice and jolly but, do we really need to have these guys appearing on anything else but their private cardboard boxes in some lonely park at dawn? Hope not!
Would the NBR be contacting the professors mentioned in the article for their responses?
One must assume that the directors of the National (party) Business Review are not really interested in scientific accuracy but in distributing business friendly propaganda. And behold, adjusting to the coming climate change problems is not a “good news story” lightly spun. Especially when a significant element of the NZ in-crowd is cashing in on rebuilding ChCh despite the long term issues with the location.
And casting doubt and causing delays over ANY government regulation and policy development was always the prime strategy of any business lobby there ever was!
I still remember the silly struggle of the German car industry against the mandatory introduction of catalytic converters. It was the ‘End of the free market’ and the ‘End of the German car industry and their competitiveness’ that was forecast by the cryers in pay of the industry… fast forward a decade and all that nonsense was forgotten….
Which “in crowd” that are “casing in” are you referring to?
A substantial number of Christchurch residents have had severe long term running battles with insurance and EQC, in some cases leading to mental and marriage breakdowns.
There are some business opportunities, but for the most part it is a long hard slog.
The coastal hazards issue was the final kick in the guts for many.
Yes, people will get used to loss of equity and property rights, but this doesn’t make for a fair outcome.
Reaction against any change is a widespread instinct.