Former ACT MP Muriel Newman — an extreme right-winger and no stranger to the wilder shores of climate denial — has waded into the debate about sea level rise and coastal hazards in Christchurch in a long-winded and unhelpful article at her NZ “Centre for Policy Research” web site. In many respects, her piece is par for the Hidebound course — full of misdirection, misrepresentation and schoolgirl errors of fact, motivated by a weird world view:
The reality is that unfortunately, carbon dioxide is being used as a political football. When radicals embraced the environmental movement in the seventies, driving out people like Dr Patrick Moore the founder of Greenpeace, they used the climate debate to conceal their real agenda – the global redistribution of wealth.
Newman takes as the text for her sermon a piece by Mike Kelly, a New Zealander who is a professor at the University of Cambridge in the UK. His offering is just as ill-informed as Newman’s — can it really be the case that a professor of technology, whose main expertise is in “advanced electronic devices for very high speed operation”, doesn’t understand the difference between weather forecasting and climate modelling? Perhaps Kelly should read a few introductory texts on climate modelling before pontificating so publicly — and so erroneously.
But what makes Newman and Kelly’s articles so unhelpful to coastal residents in Christchurch and elsewhere is not the parroting of climate denialist tropes, but the conclusion she reaches:
The Christchurch Council – and all other councils around New Zealand for that matter – should base their coastal hazard projections, on what has happened in the past. There is no perfect predictor of the future, but looking at what has actually happened in the past is better than seizing on unreliable models developed by those driving a political agenda.
Let’s do what Newman wants, and forget modelling future sea level rise. Let’s look at the past.
During the last interglacial period, about 125,000 years ago, atmospheric CO2 stood at about 300 ppm, global temperatures were less than one degree warmer than now, and global sea level topped out at 6 m above present.
The last time CO2 stood at today’s level of 400 ppm was around 3 million years ago, during the Pliocene. Global temperatures were a degree or two warmer than no, and sea levels were 20 m higher.
These facts from the climate history of the planet should provide the context for any discussion of future sea level rise. They establish that we are already committed to multi-meter increases — unless we can radically reduce atmospheric CO2, and quickly1. There’s not much sign of that happening…
The policy relevant question is therefore not how much sea level rise to expect. Paleoclimate studies tell us where we’re heading. The big question is how fast the great ice sheets of Greenland and Antarctica will melt and deliver that rise to our coastlines.
Climate models can help give us an idea of how quickly and how much the oceans will warm (and therefore expand) over the next century, which gives us a baseline increase to consider. However, the behaviour of the ice sheets as those oceans warm is much less well understood.
Ice sheet modelling is progressing in leaps and bounds, and we’re learning a great deal about Antarctica and Greenland as scientists explore ever more remote regions and gather more data, as this excellent article by Jamie Horton at the NZ Herald demonstrates. As we learn more, the news becomes bleaker, with parts of West Antarctica probably past the point of no return, and worrying signs that chunks of the huge East Antarctic ice sheet are beginning to stir, as CSIRO’s Dr Steve Rintoul discussed in an interview on RNZ National’s Nine To Noon this morning.
But it is still very difficult for scientists to give confident projections for future ice melt. Ice sheet models are improving all the time, but being conservative, glaciologists talk about multi-meter rises taking hundreds to thousands of years. If that is the case, why should we worry in the here and now?
The answer is straightforward. Substantial sea level rise is now inevitable. At some point in the future, large parts of the coastline of NZ are going to be flooding regularly, erosion will increase, storm surges will become more damaging, estuaries will expand inland, aquifers and wells will suffer salt incursions.
What we have to look at is risk, which is usually defined as probability of an event multiplied by the consequences of that event. We know that sea level rise is to all intents and purposes certain, so the answer simplifies to the value of the coastal assets in danger. That value has to take into account the expected life of the asset being considered, and their strategic importance.
There are two courses of action available: retreat — preferably managed sensibly, rather than forced by extreme events — and defence. Defence – especially against multi-meter rises where the maximum rise is not clear — is expensive, and not always possible.
The Christchurch council is investigating a tidal barrier across the Avon estuary to protect the city and its suburbs from increased flood risk. This might buy the city some time if sea level rises at the low end of current projections, but can’t be a long term “solution” unless the city is also prepared to build a network of Dutch-style dykes along the coastline to the north and to the south.
The current argument in Christchurch is about the impact of council proposals to establish coastal hazard zones. Residents fear that their land and properties are being devalued by the council action, and in particular by what Newman describes as its adoption of the “extremist” and “radical” projections of the IPCC.
What Newman suggests is that sea level projections should be based on recent, local — she calls it “beach by beach” — sea level rise, and ignore any future modelling. In the face of inevitable multi-meter sea level rise, I can imagine no better way to condemn the ratepayers of Christchurch and the taxpayers of New Zealand to an unnecessarily expensive, unpleasant and painful future.
The extremist here is Newman, but sadly her views are finding some support amongst coastal residents, as a look at their Facebook page shows. I can understand the temptation to argue that if sea level rise is only going to be small, or not happen soon, the matter can be ignored for now, but the danger is that this will encourage further coastal development — both residential and in terms of infrastructure. This will only increase the long term costs to be faced both by coastal residents and Christchurch ratepayers.
It may well be that the Christchurch council could and should handle the process of creating and implementing its coastal hazard zones in a better way. Consultation and consensus building is the only sensible way forward. But this can only happen if all sides understand what’s really going on with our oceans. Newman-style ideological climate denial has to be seen to be a fringe view, and not one that any sensible, risk-averse group of ratepayers can afford to adopt or promote. Those pushing climate denial to their neighbours should shut up.
However, one thing certainly isn’t the council’s fault. The current government has refused to deal with sea level rise at a national level, preferring to leave the responsibility to local and regional councils. While there is a clear need for local knowledge and input, there needs to be a national framework for both the science of sea level rise and approaches to dealing with it.
Without that framework there will be a piecemeal response, a patchwork of approaches. What’s happening now in Christchurch will be repeated everywhere. There will be unnecessary court cases, great stress for coastal property owners, and greatly increased costs for all tax payers. It’s going to be hard enough to deal with the reality of rapidly rising seas without handicapping ourselves by putting the issue in the too hard basket.
Sea level rise is a huge national and global problem which won’t go away just because a few ideologues are trying to mislead the public about the science. It needs an urgent national conversation on how to deal with it — something a responsible government would lead rather than ignore. After all, nothing can be said to be certain, except death, taxes and sea level rise.
- Plus, we have to be really, really lucky. [↩]