Arno Gasteiger

Three feet high and rising

With predicted increases in sea level of a metre or more by the end of this century, present-day problems of coastal erosion, flooding and salt-water intrusion into groundwater are going to get much worse. As world leaders gather in Paris to seek a political solution to climate change, it’s timely to ask how we in New Zealand are responding to the challenge of rising seas.

Written by       Photographed by Arno Gasteiger

Baches teeter on the cliff edge near Cape Palliser, on the geologically unstable Wairarapa south coast, which, like other high-energy coastlines around the country, is retreating by up to a metre a year. As well as elevating sea levels, climate change is expected to bring stronger winds and heavier rain to many regions—a recipe for more severe erosion. Beachside residents often expect councils to protect their shores, but in a country with a 17,000-kilometre coastline, the cost of keeping the sea at bay will become prohibitive.
Baches teeter on the cliff edge near Cape Palliser, on the geologically unstable Wairarapa south coast, which, like other high-energy coastlines around the country, is retreating by up to a metre a year. As well as elevating sea levels, climate change is expected to bring stronger winds and heavier rain to many regions—a recipe for more severe erosion. Beachside residents often expect councils to protect their shores, but in a country with a 17,000-kilometre coastline, the cost of keeping the sea at bay will become prohibitive.

Ray and Bev Christiansen’s place on the sandspit at Mokau, 80 kilometres north of New Plymouth, is honest-to-goodness Kiwi in a way that makes you proud. Shrubs and succulents spill out on to the grass verge in front of the white-painted weatherboard house. Out back is a vege garden, neatly terraced and filled with the kind of black tilth that only comes from decades of care. Ray points to the last of a crop of parsnips that “did us all winter”. There aren’t a lot of spring seedlings in yet. Ray is getting over an illness that has kept him out of the garden for months.

Past the parsnips, it’s just a few steps to the top of the section and the edge of the sand cliffs. Ten metres below, Tasman swells are smashing into a wall of heaped boulders. The waves look an impressive size to me, but Ray says the sea’s calm today. “In a big sea we’d be getting our feet wet standing here.”

Beyond the cliff edge, though it’s hard to imagine, there were once houses. Houses and a road and dunes that the residents used to cross to reach the sea—50 or 60 metres of land. One by one, the houses had to be removed as the sea carved back the dunes. You can see the most recent of them vanish on successive satellite images on Google Earth. Google’s current map of Mokau still shows a section between the Christiansens’ and the sea, but that property—13B Point Road—is now mostly thin air.

Ray and Bev are the last “permanents”, as they call themselves, on the seaward side of the road. They’ve had their section for 40 years. For the first 20, they came for holidays from New Plymouth.

When Ray retired from his job as a motorcycle mechanic, they moved here permanently—though that’s hardly the right word for their situation. A few big storms and their property could crumble into the sea.

Earlier this year, the end of their road, where it meets the river mouth, washed away—a tennis-court-sized slab of land gulped by the sea overnight. The district council patched up the road and armoured the adjacent foreshore with boulders, but it won’t assist the Christiansens to take similar action to maintain their barrier. In fact, both district and regional councils forbid any further protection work.

For Ray and Bev, this feels like a betrayal. “They’re supposed to be for us, not against us,” Bev tells me. She spreads out photo albums to show the history of the residents’ attempts to hold back the sea. There was the “great wall of wool bales” of ’94, when dozens of wool sacks were filled with sand and rocks and stacked into a barricade. The sea made short work of them, splitting the fabric and spilling the contents. Residents tried fences of tyres and ponga logs, but that failed, too. So in 2006, they dug deeper—into their pockets and into the beach—and contracted an earthmoving company to erect a barrier of 70-tonne boulders. Ray says this wall—illegal, because it was built without a resource consent—has worked, and there hasn’t been any significant erosion in the past five years. But without ongoing maintenance its protection won’t last.

“All we want is to be able to maintain what we’ve got,” says Bev. “But we’re not allowed to. The council won’t let us bring a digger on to the beach. We keep getting letters from the council that we’ve got to have our evacuation plans in place and all the rest of it. Well, if they want us out, they should buy us out.”

That’s not likely to happen. Waikato Regional Council’s position is that the cost of coastal real estate makes the purchase of at-risk properties unaffordable, and that individual purchases would lead to a general expectation of compensation for any property owner who found themselves in the Christiansens’ predicament.

Without compensation or permission to defend your property, or assistance to relocate your home—that’s a difficult pill to swallow. “There’s only three of us on the point now, three permanents, and the other two are on the other side of the road, so it doesn’t affect them,” says Bev. “The rest are holiday homes. It’s not the same for them as it is for us. They have other places to go to. We don’t.”

Fifty years ago, there were houses and a road in front of Bev and Ray Christiansen’s place at Mokau, on the Taranaki coast. The sea has clawed back that land, and high seas now wash up to the Christiansens’ fence. Residents banded together to protect the dune edge with boulders, but the council has forbidden any further protection work. “We’re probably sitting on a time bomb,” says Bev.
Fifty years ago, there were houses and a road in front of Bev and Ray Christiansen’s place at Mokau, on the Taranaki coast. The sea has clawed back that land, and high seas now wash up to the Christiansens’ fence. Residents banded together to protect the dune edge with boulders, but the council has forbidden any further protection work. “We’re probably sitting on a time bomb,” says Bev.

With the clarity of hindsight, the spit should never have been developed. Against the warnings of the local authority that the land was subject to cyclical erosion, in 1956 the government pushed ahead with a subdivision. Barely were the sections sold before some of them started to erode. The affected owners were refunded, and for a while the situation remained stable. Properties were built on, subdivided and sold, often for a handsome capital gain. Then the sea really started to bare its teeth, and today the remaining spit residents face the prospect of eventual loss.

On the other hand, Ray and Bev and dozens of others have had 40 years of living in the place of their dreams. The question is, when, how and who decides when the dream is over?

Waitomo District Council CEO Chris Ryan says that question can be answered only by the community as a whole. Most of the residents of Mokau live on higher ground, he explains to me in the council’s offices in Te Kuiti. It’s only the properties near the river mouth that are threatened by erosion. “Residents who live further back want the council to stick to its policy that you cannot intervene in what is a natural process,” he says. “When they were asked if foreshore protection works were something they as a community wanted to pay for out of their rates, the answer was no.”

“Our section will go eventually, with global warming,” Ray admits. “We can see that. But in the mean time I can still catch fish off my back lawn.”

On matters of coastal management, councils take their cue from the government’s 2010 New Zealand Coastal Policy Statement, which discourages hard protection structures while encouraging “change in land use, where that would reduce the risk of adverse effects from coastal hazards, including managed retreat by relocation or removal of existing structures or their abandonment in extreme circumstances”. Essentially, the statement says: Keep development out of areas vulnerable to natural hazards. But what if you’re already in one?

“Our predicament,” Ryan tells me, “is how do you apply a regulatory framework that has been developed in the now to a circumstance that has been created over time?” The council’s solution is to try to keep the road open so that it’s available and safe for people to “move their assets out” (ie relocate their houses), while maintaining support for residents who have emotional as well as financial capital invested in their properties.

“They’re our ratepayers, we are their council, and we have to work with them to find a solution to a problem that neither party is to blame for,” he says.

The Christiansens are resigned to the inevitable.

[Chapter Break]

The situation at Mokau isn’t unique or even unusual. Every coastal region has a community battling to preserve its most vulnerable land. Every region has risky beach subdivisions where developers—or the government itself—played blackjack with nature, and lost. Coastal erosion is a fact of New Zealand life. But it is escalating and intensifying, and will continue to do so for several centuries as sea levels rise.

I could tag that last phrase with the words: “That’s the consensus among climate scientists.” But that’s like saying there’s a consensus that New Zealand will have El Niño weather conditions this summer. We’re beyond consensus. It’s happening. Global mean sea level has risen 1.7 millimetres per year over the past century, rising to just under three millimetres per year in the past two decades. Climate scientists predict a cumulative global rise of about a third of a metre by 2050 and a metre by 2100.

Such a rise in sea level will redraw Earth’s land–sea boundaries. New Zealand has one of the longest coastlines of any country—around 17,000 kilometres. Sixty-five per cent of our communities and major infrastructure lie within five kilometres of the sea, and 12 of the 15 largest towns and cities are coastal. The impacts and implications of a half-metre or metre vertical rise in mean tide height—to say nothing of add-ons such as storm surges, king tides and tsunami waves—are both scarily profound and profoundly scary. Sea-level rise will be the biggest geographical change Aotearoa has experienced since voyagers from Hawaiki stepped ashore in the 14th century.

“We have gone inside the lion cage,” says coastal engineer Jim Dahm about our propensity for building next to the sea. On the Cape Kidnappers coast, the shoreline retreated by tens of metres following the Napier earthquake in 1931, and chronic erosion has continued. When king tides combine with high swells, the seaside baches of Haumoana take a hammering. But residents have no intention of giving in. “Nothing a bit of drying won’t fix,” said the owner of this home after storm waves broke a glass door and flooded the interior in 2011.
“We have gone inside the lion cage,” says coastal engineer Jim Dahm about our propensity for building next to the sea. On the Cape Kidnappers coast, the shoreline retreated by tens of metres following the Napier earthquake in 1931, and chronic erosion has continued. When king tides combine with high swells, the seaside baches of Haumoana take a hammering. But residents have no intention of giving in. “Nothing a bit of drying won’t fix,” said the owner of this home after storm waves broke a glass door and flooded the interior in 2011.

To see what a metre rise in sea level might do to a city, you need look no further than Christchurch, where some areas in the north-east of the city dropped by up to a metre during the 2010/2011 earthquakes. The main difference between rising seas and the city’s subsiding land was that “we got it straight away”, says Deirdre Hart, a senior lecturer in coastal studies at the University of Canterbury.

“The earthquakes have given us a laboratory for exploring the impacts of that level of rise,” Hart tells me while she takes a break from writing a grant application for further coastal hazard research. One of the early lessons from ‘laboratory Christchurch’ is that we need to expand our definition of ‘coast’, she says. Beaches, shorelines, cliffs—these are just the coastal fringes. The area of vulnerability to rising seas is “everything that’s physically, ecologically and humanly linked to the ocean and affected by the ocean”. And for a city like Christchurch, built on porous sediments deposited since the last ice age, that’s more than half the urban area.

“Most people think of the sea-level threat as water rising up at the coastal fringe and coming over the dunes or the spit and inundating adjacent low-lying areas,” says Hart. “That’s not the lesson we’ve learned at Christchurch. What we’ve learned is that we are surrounded by water, all of which is connected to the ocean, and all of which can be affected by rising seas.”

There’s the water we don’t see, for instance—the groundwater beneath our feet. Large parts of the city are now closer to that groundwater because the land subsided. Areas in the low-lying east of the city have saturated soils and a thinner surface crust, making them more prone to liquefaction.

“We’ve also got rivers running through the city which need to drain down the ocean ‘plughole’,” says Hart. “If that plughole is blocked because sea level is coming up, the rivers can’t drain effectively and you get a backwater effect that can result in flooding several kilometres inland.”

Other impacts include saltwater contamination of aquifers, changing depths and sedimentation regimes in estuaries and ecological effects caused by a changing freshwater/saltwater balance, including loss of habitat for wading birds and feeding grounds for īnanga (whitebait).

“So sea-level rise isn’t something out there on the edge, like a melanoma on your skin, it’s inside the city’s immune system, through our waterways and aquifers,” says Hart.

With such a diagnosis, how should a city like Christchurch respond? By focusing on the multiple impacts that sea-level rise will create, says Hart. “It’s pointless to respond to sea-level rise on its own as if it’s a single hazard. We need to look at all the related hazards, especially in places where development has been inappropriate, because these will be the pinch points as sea level rises.”

Brighton Spit, a four-kilometre-long finger of sand that encloses and protects the Avon–Heathcote Estuary, is one of those pinch points. As well as being vulnerable to inundation from rising seas, the spit faces several other threats: seismic hazards, storm-induced erosion, and tsunami affecting both the seaward side and “wrapping around to come in the back door from the estuary”, says Hart. “Limiting the response to just one of these hazards”—building a seawall to combat erosion, for example—“could compound the risks from the others.”

Sea-level rise conjures up images of eroding coastlines and encroaching waves. But in a largely low-lying city like Christchurch, the primary hazard associated with rising seas is flooding. The recent earthquakes gave the city a foretaste of that impact. On the day of the deadly February 2011 quake, suburbs in the east—such as Bexley, built on a reclaimed wetland—suffered liquefaction and slumping equivalent to the predicted 100-year rise in sea levels. State Highway 74, running diagonally from top to right in this view, was under water, as were most other roads. Bexley was red-zoned, and almost every house visible in this image has now been demolished. “The swamp is starting to reclaim our city,” says University of Canterbury coastal scientist Deirdre Hart. “The level of water through our waterways, the groundwater system and the ocean is higher now compared to where our land is sitting.”

The importance of a multi-hazard response is signalled in the national coastal policy statement, which says that special consideration must be given to situations where “significant adverse cumulative effects are occurring, or can be anticipated”—but it is left to local bodies to figure out how that consideration should be translated into policy and implemented. In Christchurch’s case, implementation has produced an irate backlash from residents.

The trigger was a 2015 report commissioned by the Christchurch City Council and conducted by environmental consultancy Tonkin and Taylor that assessed coastal erosion and flood hazards over 50- and 100-year timeframes. The report identified almost 18,000 homes that were at risk from coastal flooding and 6000 at risk of erosion associated with a one-metre rise in sea level (the 100-year scenario). The council immediately flagged those vulnerabilities on the affected properties’ Land Information Memoranda—publicly available reports that summarise relevant details pertaining to any parcel of land. Simultaneously, the council announced its intention to limit new development in the at-risk areas by revising the district plan.

Both were reasonable responses, on the face of it, considering the council’s obligation under the Resource Management Act and other legislation to identify areas subject to natural hazards and to control the use of land so as to avoid or mitigate those hazards. But residents whose properties were affected by the decision were infuriated at being peremptorily “red-stickered” in this way, claiming that the council’s actions would diminish the value of their properties, make insurance more difficult to acquire and limit their development options.

Tim Sintes, a retired commercial fisherman, is one of the residents who are taking the council to task. To reach his home in Southshore, on Brighton Spit, I drive along Rocking Horse Road, which turns out to be aptly named.

Every 50 metres or so the road has a hollow in it where underground pipes have been laid and the fill used to bury the pipes has slumped in the earthquakes. It’s like riding a roller coaster.

Most of the side roads are named after birds: heron, plover, kingfisher, petrel, stilt. Sintes lives at the end of Tern. His property merges with the dunes. He dons a jacket and we walk through windswept marram grass and coastal vegetation and down to the beach.

“This coast has been accreting for decades,” says Sintes, who has a collection of historic photos (and personal memories from having fished up and down the Canterbury coast) to verify the spit’s expansion. “At the moment, we’re getting two metres forward growth a year.”

The evidence on the ground is convincing. Sintes points out a recently installed handrail beside an access path to the beach that is now no more than ankle high above the sand. A gazebo that stood at the water’s edge now has an excellent view of a field of marram. In summer, he says, bulldozers are needed to clear the sand from the fences used to promote dune growth at Brighton Beach. “We’re seeing the opposite to what they’re telling us.”

Maybe so, but coastal scientists say that accreting coasts can turn into eroding coasts on a figurative dime. All sorts of physical events—seismic, oceanographic, geological—can slow, stop and reverse sedimentary processes.


In Brighton’s case, the sand currently being deposited on the spit is coming almost exclusively from the Waimakariri River, which empties into Pegasus Bay north of the city. A good half of the Waimak’s sediment load is shifted southward by longshore drift generated by wave refraction from southerly swells. A half-metre sea-level rise is likely to cause the drift to reverse, carrying sediment north and away from the Christchurch dunes. As a consequence, the dunes are predicted to retreat by 60 metres in the coming century—almost to Sintes’ front door.

Although some residents question the scientific basis of the council’s decision, most object to the way the council has acted: too hastily, they say, with too little consultation, and without regard for the fact that people are still in recovery mode from the earthquakes.

“People are a bit critical down here because the timing sucks,” says Sintes, who serves on the local community board. “You’ve just driven here. You know what the road’s like. It works on your brain. It wrecks your car. People are still trying to get insurance five years after the earthquakes, and suddenly to get this on top.

“We’re not dots and lines and hazard shadings,” he says, “we’re homes and families.”

Sintes drives me to the end of the spit, pointing out various vacant sections as we pass. Development plans have halted in their tracks by the council’s actions. “These are valuable sections,” he says. “When you’re suddenly told you can’t build on them and council is not going to do anything about it, that’s theft. There’s a saying, ‘You’ve got to do the crime before you do the time.’ The way we see it, the council has jumped the gun. It’s a bit like me putting a sticking plaster on my finger today because I might cut myself next week.”

Beyond the road end is a reserve where Sintes and other community members are revegetating the dunes and restoring habitat for seabirds. The first group of the season’s godwits, fresh in from Siberia and Alaska, are feeding on the mudflats. Sintes is enthusiastic about the work—he says his group recently won a ‘best dune restoration’ award—but fears that the council’s long-term agenda may be to let the entire spit revert to nature.

Yet that outcome may not be in the council’s power to decide—or the residents’. If Tonkin and Taylor’s modelling is accurate, in 100 years the spit will be only a third as wide as it is today. Considering that almost the entire width has been built on, that means two-thirds of Southshore’s residents will need to find somewhere else to live. They may have to retreat.

[Chapter Break]

There’s a road that hugs the coast south of Oamaru called, unsurprisingly, Beach Road. A stretch of this road has not seen traffic since 2008, and that is because much of the road is missing. In places, the centre line disappears into a gaping hole. Elsewhere the entire road has gone, undermined by the waves.

A paint-peeling southerly is blowing and the sea is discoloured from recent rains. I count the seconds between the dull green curlers breaking offshore—ten seconds a wave, six waves a minute, three million waves a year. A 2002 report estimated that this part of the coast has been eroding by a metre a year for almost 30 years. Despite the pleas of some locals to preserve what is undeniably a stunning stretch of highway—for tourism opportunities as much as for local enjoyment—the Waitaki District Council is refusing, considering it money thrown into the ocean.

Instead, the council is negotiating to buy land so that the road can be moved inland and away from the hazard zone. In other words, a ‘managed retreat’, as specified in the Ministry for the Environment’s guidance manual for local government on coastal hazards and climate change. The ministry’s definition of managed retreat is “any strategic decision to withdraw, relocate or abandon private or public assets that are at risk of being impacted by coastal hazards”.

‘Retreat’, however, is not a word many people want to hear. It implies, and even sounds like, ‘defeat’, and our entire cultural conditioning is such that we reject the idea of being quitters. We prefer a more Churchillian approach, squaring the jaw and growling, “We will fight them on the beaches.”

Heroic defence appeals to our frontier mentality. It is more our style than strategic surrender. It also appeals to the notion of Kiwi ingenuity, the can-do competence for which we’re famed. We like stories about men with diggers mustering on the beach at dawn to open the entrance of Mangawhai Harbour, as they did in 1991.

But the reality is that with a one-metre sea-level rise, human intervention will become increasingly futile, and our vaunted mastery over the elements will be a concept increasingly confined to history books describing the days before humanity overshot the atmospheric sweet spot that has kept the planet’s climate stable for the past 10,000 years.

And a one-metre rise is just the start. A prevalent misconception with climate change is that if we succeed in bringing greenhouse-gas emissions under control, the sea will obligingly stop rising. Not so, says Rob Bell, a coastal oceanographer with NIWA. “The real sting in the tail is that sea-level rise will be the last climate variable to respond because of the huge latent heat storage in the ocean,” he tells me. Even if global emissions are stabilised by the end of century—one of several scenarios laid out by the United Nations Intergovernmental Panel on Climate Change (IPCC)—seas will continue rising for at least another 100 or 150 years, with an increase of 1.5 to 2 metres above current mean sea level likely.

Like throwing a double six, when spring tides coincide with north-east gales, Auckland’s Tamaki Drive—an important commuter route between the city and the eastern bay suburbs—gets it in the neck. As sea levels rise, the odds of that combination will increase. A rise of 0.4 metres, expected by mid-century, will make what is currently a 1-in-100-year flooding event an annual occurrence.
Like throwing a double six, when spring tides coincide with north-east gales, Auckland’s Tamaki Drive—an important commuter route between the city and the eastern bay suburbs—gets it in the neck. As sea levels rise, the odds of that combination will increase. A rise of 0.4 metres, expected by mid-century, will make what is currently a 1-in-100-year flooding event an annual occurrence.

Much more catastrophic is the BAMA scenario—the burn-it-all, melt-it-all option, in which all known fossil-fuel deposits are combusted, all the ice sheets and glaciers melt and Earth’s oceans rise 70 metres. That’s the business-as-usual path, and there are plenty of people still walking it.

Whichever scenario plays out, we’re slouching towards Atlantis. And so retreat is inevitable. There is simply no avoiding the fact that in 100 years, with seas still rising from the ‘baked in’ temperature increase brought on by historic greenhouse-gas emissions (not the 32 billion tonnes of carbon dioxide we’re emitting every year at present), many coastal residential areas will become disaster zones. Armouring kilometre upon kilometre of coastline is not an economic option for a country with a coastline like ours. (The Dutch, valorised as coastal defenders ever since Hans Brinker put his finger in the dike, have a mere 451 kilometres of coastline, less than three per cent of ours, but a GDP four times greater than New Zealand’s. They can afford to armour their coastline; we can’t.)

At least 15 years ago, Bell warned that coastal development and global warming are on collision course and that “managed retreat and adaptation are the only reasonable long-term options”. Yet for most communities, retreat from coastal hazards is not only not on the table as an option, it’s not even a topic of conversation. We’re still fiddling while foam churns.

[Chapter Break]

What would managed retreat at a community scale even look like? It’s one thing to write off a damaged road and build a new one back from the coast, quite another to shift the people and infrastructure of a residential and commercial area such as South Dunedin, which finds itself in an environmental squeeze between rising groundwater, a stormwater system with no spare capacity and pounding surf that regularly damages the city’s barricades.

Like parts of Christchurch, Wellington, Auckland and many other coastal cities and towns, South Dunedin was developed on a wetland. It had a name, Kaituna, and it lay between the St Clair hills and the Otago Peninsula; it was a source of eels, pūkeko and weka for southern Māori.

Thriving colonial Dunedin needed land to expand, so in the 1850s, the swamp was filled in, partly with sand mined from the protecting coastal dunes—an act of folly that was decried by residents even as it was happening. The area became known as “The Flat”, but it could equally be called “The Low”, because much of the reclaimed land is lower than the mean high-water spring-tide mark. Groundwater lies a mere 0.3 to 0.7 metres underground. In the winter of 2015, the area suffered disastrous flooding when 175 millimetres of rain fell in 24 hours. Neither the soil nor the stormwater system could cope with the deluge.

To get a sense of the scale of South Dunedin’s challenges—which have prompted the mayor to speak of an “end game” of retreat for parts of the suburb—I meet council policy analyst Maria Ioannou on the St Clair Esplanade, near its famous shark warning bell and a signpost pointing to the South Pole, 4897 kilometres away—plenty of fetch for storm waves from the Southern Ocean to deliver not only excellent surf but also a battering ram to St Clair’s seawall. And, indeed, there are plastic safety barriers surrounding holes in the esplanade’s paving where the sea has undermined the structure—the latest damage in a cycle of destruction and repair that has been happening since the 1870s.

Ioannou and I walk along Ocean Beach, past the piles of a failed groyne that are beginning their slow tilt to oblivion.

Random lumps of brickwork and concrete are being disgorged from the dune face and littering the sand. At the top of the dunes, slabs of asphalt from former paths and parking areas jut into space. Ribbons of orange hazard tape flutter in the wind.

South Dunedin was built partly on industrial debris, Ioannou says, hence the rubble in the dunes. There are a lot of toxic unknowns in that historic landfill that are slowly coming to the surface, causing yet another headache for a suburb facing the threat of inundation from a combination of rising seas and an inability of the land to drain effectively.

We turn inland to the grid of streets and tightly packed houses. South Dunedin is one of the most densely populated and socio-economically vulnerable suburbs in the country, with a prevalence of elderly and low-income residents. Ioannou, who leads the council’s climate change adaptation planning, says that one of the problems in even thinking about managed retreat—the “non-protection option”, as it is euphemistically termed—is that there is no model for it. In New Zealand, the only examples have been the relocation of a couple of surf clubs and car parks. And even overseas, there are few examples of community relocation in response to coastal hazards.

The impulse to place a barrier between land and sea is strong, but can lead to a conflict of interests. New Zealand’s guiding environmental legislation, the Resource Management Act, states that the preservation of the natural character of the coastal environment is a matter of national importance. Most protection structures (seawalls, groynes, etc) not only fail to preserve natural character, they can also contribute to its loss. “Rock walls are very effective at protecting development behind the wall, but they degrade values in front of the wall—beach values, amenity, recreational values, natural character,” says Thames-based coastal engineer Jim Dahm. “If you’ve got a retreating shoreline then the effects of seawalls are particularly severe because you eventually lose the beach.” To safeguard vital infrastructure such as main roads from coastal hazards, so-called “hard protection” measures are considered essential, even though they can have negative environmental effects. A project to add traffic lanes to Auckland’s northwestern motorway where it crosses the upper Waitemata Harbour at Waterview (pictured) has included placing thousands of tonnes of rocks beside the causeway to absorb wave energy, despite the adjacent area being a marine reserve and seabird nesting area. The road surface has been raised to accommodate a 0.8-metre rise in sea level by 2100, and a wide foundation allows for more height to be added as required. There are alternatives to hard structures, such as beach nourishment (bringing in sand from elsewhere), dune enhancement (planting dunes with sand-binding vegetation), and various soft engineering options such as using permeable fabrics called geotextiles to hold sand in position while the beach grows naturally around and over them. Coastal engineers tend to favour these more natural solutions, but often residents expect and demand something solid that appeals to their sense of coastal defence and “holding the line” against the sea. In surveys of public attitudes towards coastal protection, hard engineering solutions are typically favoured. One respondent made his preference very clear: “Rocks, BIG rocks, THOUSANDS of rocks.” Many beachgoers seem to have a split personality when it comes to preservation of coastal amenity. While they appreciate beaches for their natural endowment of sand, surf, dunes and vegetation, they expect artificial structures and methods to be used to preserve the status quo, rather than allowing natural processes to prevail. But as sea level rises, economic pragmatism may lead to a shift in perceptions, since maintaining coastal protection structures will become prohibitively expensive. Perhaps, too, as society shifts away from a humans-against-nature ethos towards a more integrated humans-in-nature sensibility, public opinion will favour managing human interests rather than managing coastlines. As Otago University School of Surveying lecturer Mick Strack puts it: “We cannot afford, economically or environmentally, to hold back the sea.”

To address this deficit, coastal geomorphologist Paul Kench, head of the University of Auckland’s School of Environment, is leading one of the National Science Challenges, called ‘Living on the Edge’. For four years from 2016, a multidisciplinary team from 15 separate research institutions will work in Hawkes Bay, helping communities at risk from coastal hazards to plan their way through the next century.

“We’ll be trying to lead them through a process of asking, ‘Given the intensification of hazards, what do you want for this community in 50 years’ time?’” says Kench. The aim is to create a prototype for community adaptation to sea-level rise. “We’ll start with community, build some trust in the science, then use that trust to plan for the future.”

He thinks a strong lead could come from iwi. “Māori attitudes to land might afford some greater flexibility,” he says.

In Māori thinking, land and sea are seen more in terms of continuity and connection than separation, a concept embodied in the phrase “ki uta ki tai”, from the mountains to the sea. The Waitangi Tribunal, in its 2004 report on the Crown’s foreshore and seabed policy, notes that “Māori do not separate land above high-water mark, tidal land, and the seabed as distinct entities; it is all whenua”.

“Mean high-water mark may be a physical boundary, but it isn’t a cultural boundary,” Hirini Matunga, professor of indigenous planning at Lincoln University’s School of Landscape Architecture, tells me.

“Mountains-to-sea was central to the foreshore and seabed debate, and this ethos has permeated iwi management planning since then,” says Matunga, who has whakapapa connections to several iwi, including Ngāi Tahu, Ngāti Porou and the people of Atiu in the Cook Islands. “So while there is a lot of concern about the impacts of sea-level rise—encroaching on urupā, for example—there is a real pragmatism as well, centred on the notion of ebb and flow.”

In Ngāi Tahu’s oral tradition, Papatūānuku and Takaroa, the deities and domains of earth and sea, were in union before Papatūānuku and Rakinui became ‘earth mother’ and ‘sky father’. That understanding accords with the traditional nomadic life of Māori, drawing resources from land and sea alike.

“The sea was our supermarket and our highway,” says Peter Ramsden, a kaumātua of Koukourarata/Port Levy, once the largest Māori settlement in Canterbury, now a quiet beach community at the foot of Banks Peninsula. Like many coastal settlements, Koukourarata is considering the implications of rising seas, preparing for the changes that are coming. But instead of seeing the rising sea as an irremediable threat, it sees opportunity as well.

“In this country we’ve inherited the Dutch mentality of holding back the sea,” Ramsden tells me when I telephone him. “But the traditional Māori view was always more accepting. Not quite ‘que sera sera’, but certainly more comfortable with how situations change.”

Some of those changes could be for the good, such as the reinstatement of wetlands, with their multiplicity of ecological and human benefits. In a reversal of this country’s geographical history since colonisation, some of the wetland areas most prized by Māori as foodbaskets and resource centres are likely to revert to their former aquatic state as seas advance and human development retreats. It’s tempting to see some cosmic reciprocity at work in this reverse reclamation—19th-century land modification undone by 21st century rising seas, themselves modified by human burning of fossil fuels.

“Snap the coast, see the future” is the tagline of the King Tides Initiative, which encourages people to take photographs during the highest spring tides—such as this one shot by eastern suburbs local Craig Thomson at Bucklands Beach, Auckland, in March 2015—and share them online. Today’s king tides are what a normal spring tide will look like 50 years from now. By getting acquainted with the new baseline it becomes easier to imagine and plan for a more watery future.

Ramsden points to Te Waihora/Lake Ellesmere, once a mahinga kai (food source) of legendary richness, now ecologically decimated by drainage and modification for farming. “Let’s be honest: it’s a cesspool at the moment,” he says. “This incredible area should never have been turned into dairy land. Our feeling is, let the farms go back to wetlands. Recreate the lungs of Papatūānuku.”

Coastal scientists such as Hart welcome the idea of moving away from hard protection structures and living with water. “There’s an opportunity with sea-level rise to give back the space for natural systems such as salt marshes and wetlands to operate,” she says.

The challenge of rethinking and reimagining the liminal zone, the meeting place between land and sea, is also energising the head of Lincoln’s School of Landscape Architecture, Mick Abbott. The overnight simulation of 50 years’ worth of predicted sea-level rise through the earthquakes both shattered people’s perceptions of what it means to live in an urban environment and created the chance to consider how we might use land more flexibly, he says.

“Sea-level rise confronts our views of land ownership and land use. Ownership now is not an enduring ownership. You could say that sea-level rise makes everything a genuine 99-year lease—a lease not dictated by law but by nature.”

Abbott and his students have been looking at how land use could change over time in a staged series of uses that become progressively more aquatic. For instance, roadways might become canals, bridges or floating platforms as water encroaches. Land with a high flood risk could be used for short-term benefits such as food-growing, recreational areas or experimental housing areas with relocatable dwellings. Planning with short time horizons encourages society to touch the earth lightly, he says, and reduces the risk of foreclosing future options by locking in bad decisions for long periods.

“It’s a change in thinking. Instead of the finger in the dike, or higher and higher seawalls, it’s embracing the range of options offered by the coastal zone.”

None of this adaptation needs to happen overnight. Managed retreat, as Tonkin and Taylor’s Christchurch report notes, can occur at a range of spatial scales, from individual properties to whole communities, and over a range of time scales. “It should be considered as a staged response, where assets are relocated or abandoned when the risks become intolerable.”

Hart agrees. “In New Zealand, we actually have the option to do things differently. We have the space, we have a small population, we don’t need to be building in harm’s way. We can try to build a more resilient society.”

Yet the rhetoric of holding the line is hard to shake, and that will take leadership, says Kench. “What’s needed is a strong national stance that if you’re located in vulnerable places you’re going to have to accept a managed retreat. It doesn’t have to happen in a week, but certainly within the next 30 years things are going to have to change, or the costs of defending that land and infrastructure will be enormous.”

Progress at central government level seems likely in the coming year. The Parliamentary Commissioner for the Environment, Jan Wright, is poised to release a new report on sea-level rise, and the Ministry for the Environment is working to update its guidance for local authorities on coastal hazards.

[Chapter Break]

On what happens to be the second-highest spring tide of 2015, I take a look at what the sea is doing at one of Auckland’s infrastructural pinch points, Tamaki Drive. It’s a calm day, so there are none of the fountains of spray that drench vehicles driving that route in a nor’easter. But even on this still spring morning, the stormwater grates in the road are awash, and the water is rising and falling with the swell, as if responding to the sea’s heartbeat.

In a storm in January 2011, the entire road was flooded. It was labelled a 1-in-100-year event. Bell says he uses events like this, which remain vivid in the public imagination for a long time, to communicate the implications of rising seas. With a 40-centimetre rise in sea level, the 2011 flood would be an annual event. With a metre rise, Tamaki Drive would be permanently under water.

Like a 45-metre strand of red hair, New Plymouth’s Wind Wand—honouring kinetic artist Len Lye and installed on the city’s coastal promenade—epitomises the restless westerlies that buffet the Taranaki coast. Equally persistent are the waves that pound the rock walls that armour the city’s shoreline. As sea level rises, the contest between surging waves and stationary land can only become more one-sided: the irresistible force overwhelming the immovable object. Like Lye’s wand, we must inevitably bow to the sea.

Bell says using flood events as trigger points can help communities bite the bullet on managed retreat. In Queensland, communities that had resisted top-down planning controls from the state government elected to come up with their own trigger points. If there were a certain number of exceedances—say the main street flooded three times in a year—the community would agree to leave.

“We talk now about the number of exceedances because people can identify with numbers—is five floods too many, is ten too many? How many times does Tamaki Drive have to flood before we do something?”

And so to Paris, where the hopes of the many rest on the decisions of the few. The pledges to reduce greenhouse-gas emissions—the Individual Nationally Determined Contributions—amount to a damp squib. If they are the best the nations can muster, the global temperature is likely to rise by 3.5ºC, not the 2ºC that has become the accepted default limit for a tolerably liveable planet. New Zealand’s contribution has been criticised as unambitious and inadequate.

You have to wonder: Why has the greatest challenge of our century not galvanised us into action? For a distressingly large number of people, climate change is still in the “Is it real?” category, or its more highbrow iteration, “Is the science ‘settled’?” rather than provoking the one question that really matters: “How should we then live?”

Many hope that a concern for future generations might arise as some kind of serendipitous force, a slow-rising tide of moral awareness that leads political leaders to do the right thing.

Tania Hopmans, a member of the Hawkes Bay inter-council committee on coastal hazards, tells me that kaumātua in her area often judge decisions based on a “mokopuna’s mokopuna” time scale—the impact the decision might have on their grandchildren’s grandchildren. She recounted an instance where a kaumātua was talking about climate-induced flooding of the marae, and whether the marae should be moved to higher ground. He had been born in that place, and his parents were buried there, and I could imagine the bond those two events had created between that man and that whenua, and how painful the rupture of that connection would be.

“Yes, I was born here, and my ancestors’ bones are in the urupā, and I would like to die here and be buried alongside them,” the old man had said. “But it’s not about me. I want my moko’s moko to be dry and safe.”

If enough of us hold those moko in our minds, there’s a chance they will inherit a liveable world.

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