Are we suddenly surfing an extreme climate cartoon?
One torpedo from Auckland Council takes aim at both sustainable development and sensible guidance
Catch a podcast version on this topic, as seen and heard (from 41:20) on the Hoon with Bernard Hickey’s the Kākā.
Trouble about to boil over?
There’s a pathway of ongoing turmoil boiling over around use of the most extreme climate change scenario for planning. It’s our use of a “high” version of RCP8.5 scenario (or Representative Concentration Pathway with 8.5 watts per meter squared of warming by 2100). Later, I’ll explain why it isn’t realistic, but to make its predictions practical, it averages over 4°C of warming across the globe and 3.8°C for New Zealand.
This scenario generates 1 m of sea level rise before 2100, or in about 70 years from now. More realistic scenarios reflecting the progress on the Paris Agreement would get there only 110 years later. Just as a reminder, the world currently has policies representing less than 3°C of warming and is aiming for 1.5 - 2°C of warming.
There’s a right way to use the most extreme scenario: make it a worst case as a trigger, but then do some planning in a reasonable way. And this has been the what our national guidance documents say since 2017.
The case where Auckland Council is now opposing a surf complex that plans to water using the waste heat from a Spark data centre is headed to hearing shortly. Honestly, it feels like a crazy cartoon and it may be one we’ll remember.
Interestingly, the surfing complex is a project moving forward under the 2020 fast-tracking pathway and appears to have central government’s support.
Blowing this open, Newsroom’s Jonathan Milne expanded on this with a second story, highlighting that central government appears concerned 17 councils are misusing the guidance.
What, actually, is the guidance?
The new central government guidance emerged at the end of February. If I read it carefully, it suggests the same sensible, logical approach I’ve outlined above. Yet, the new guidance is much longer (200 pages) and muddier.
The first step of the process applies the extreme scenario. That’s a problem because there’s already a precedent of councils, 5 or 10 years ago, assigning a junior planner. Inevitably, they run out of time or budget before they get to the further steps in a planning or consenting process.
There are two new problems, that have emerged predictably. Firstly, the document starts out with 30 pages of historic examples where using the high end scenario seemed appropriate, but a decade ago ice sheet models were still being developed and didn’t report as much sea level rise. These set a precedent for normalising the use of the extreme scenario.
Secondly, around page 51, the guidance meanders into the idea of ‘interim allowances’ for sea-level rise. It would be fairly easy to end up that page and in the following table on a quick read, and conclude that’s what the guidance recommends. It is not. Interim appears to be a lazy or imprecise way of making due with the extreme scenario, and not using more realistic assessment methods.
Best practice is to adopt dynamic adaptive pathways planning which would keep an eye out for key action points, and then have steps that can be taken when that sea level situation is arriving or a big event happens. For example, identify that a site is at risk when say, relative sea level rise reaches 0.8 meters. When that’s close or comes fast due to a big storm, you need to have already identified and prioritised your options.
That would have huge benefits, because planning processes would account for sea level, storm, and tsunami would be straightforward, able to fit into urban and infrastructure planning.
Is it dangerous to plan for a scenario that can’t happen?
We wouldn’t have a problem if coastal inundation guidance was used with the right logic. Yes, plan for the worst. But plan realistically.
Embracing the extreme scenario and then doing no further work at every decision would be piecemeal thinking that leads to abandoning everything near the coast whenever a decision comes up. This is unstable politically because it would be coming for everyone’s property value, and every project that develops the infrastructure and economy communities need. That’s unmanaged retreat!
And of course, there has been a goal to design legislation and processes that could support managed retreat. Unfortunately, what we’re seeing now is a worst case, which I worried would happen because of how local government planning works, as I explained above. In short, an under resourced planner stops at step one, which uses the extreme scenario, and never assesses the realistic scenarios. That becomes the precedent and the council and other councils keep doing the same thing. Check it out: they now call this “medium risk”.
Let’s keep in mind, this is a data centre! I can’t really embrace the notion it will persist beyond 2100.
Let’s back up and ask: how crazy is the new version RCP8.5 ?
Some of my favourite climate and carbon cycle scientists say things like, RCP8.5 is like going 2009, and then burning all the coal that seemed economically and technically possible for the rest of the century. And when lampooning ongoing use of these scenarios four years ago, they wrote, “When RCP8.5 or its successor SSP5-8.5 are deployed, they should be clearly labelled as unlikely worst cases rather than as business as usual.”
Ongoing use of this scenario seems insane in a world where the economic tipping point has been crossed and solar will forever be cheaper and cleaner than coal. The controversial Roger Pielke Jr has correctly pointed out that New Zealand is now among, but not alone among the most extreme misuses of extreme warming scenarios.
I should also say that by 2019, it had become clear that emissions were well below the RCP8.5 scenario. But it was at this time that updated scenarios (like SSP5-8.5) came along that fudged the atmospheric concentrations back to historic observations. So we still have people mistakenly claiming that observed emissions match the extreme scenarios.
But it gets worse. A scenario known at SSP5-8.5 H+ represents the very high end (85th percentile) model runs of the already extreme scenarios. That’s how we get to 3.8°C of warming in Aotearoa New Zealand by 2100. It follows that this has become the highest scenario that serves as the trigger for appropriate use of more realistic scenarios. But oops! That also means it is likely to inappropriately used, just as we’re seeing with Auckland Council.
"But it failed to use the new “up-to-date climate change factor” of 3.8°C warming that the council now requires, according to the council’s senior stormwater engineer” -Newsroom article
So What? How big is this?
I think this is big because it shows up the same errors our planning processes are capable of that have led to the housing shortage, and similar problems. We seem to assume markets and bureacracies sort this stuff out. But that doesn’t even work well in big countries like the US or in Europe. Just look at the Wellington IHP process to understand how crazy our system can get!
We really need some steering, tyre kicking and gap filling in a small country like Aotearoa. Doing so is the aim of this substack – bolstering the necessary level of environmental integrity.
The longer we continue to much this up, the more likely it is to lead to polarisation around false solutions like the new RMA Fast-Tracking.
Or maybe we’ll be surprised? It turns out that ACT’s Simon Court, in carrying out his Undersecretary for RMA Reform agrees broadly with what I’m saying here and wants the dangerous and problematic use of the SSP5-8.5 H+ scenario squelched as well.
In passing, it may be worth linking the first time I raised this as an emerging issue back in mid-2022. I didn't get full implications we're now seeing covered in this article, but tried... https://www.stuff.co.nz/environment/climate-news/129492959/an-unrealistically-hot-forecast-for-2100-could-hurt-your-property-values
Thanks Troy. There is discussion of this point in the guidance (Box 3 on page 41). They note
- SSP2-4.5 H+ reaches the same SLR just a few decades later than SSP5-8.5 H+.
- SSP5-8.5 H+ still not take into account the risks of further polar ice changes leading to more rapid SLR
- SSP5-8.5 is less likely than thought a decade ago, but still possible
- high-end impacts may still result from a lower emissions scenario
and several other points.
To which I would add that even a 17% tail-end risk (used in the H+ scenarios) is pretty high.
Dynamic Adaptive Pathways are recommended and discussed - I guess the question is whether this will lead to councils adopting them.
Meanwhile, councils are coping with organised climate denial groups pressuring them to drop the higher-impact scenarios.