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Rising sea levels are putting our coasts in crisis – should we adapt or retreat?

Haumoana, Hawke’s Bay, in July 2017. Photo/Tim Whittaker

Rising seas will overwhelm many of our coastal regions unless we move fast. Whether to protect or retreat from low-lying areas – either option carries considerable economic, social and environmental costs and it’s a debate communities cannot tackle in isolation. 

We are good at sensing danger. Some dangers anyway. Faced with a guy with a knife or an animal with big teeth, says climate change commentator Jeff Goodell, we humans have evolved to defend ourselves, “but we are not wired to prepare for the barely perceptible threats that gradually accelerate over time”.

Such as sea-level rise, writes Goodell, in his prosaically titled The Water Will Come: Rising Seas, Sinking Cities, and the Remaking of the Civilized World. With the rising tide already gnawing at coastal regions around the globe, by the end of this century, hundreds of millions of people will be forced to retreat inland, “but that is the part no one wants to talk about.”

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Goodell, a contributing editor at Rolling Stone magazine, is the author of several critically acclaimed books on climate change and energy issues and was in New Zealand earlier this year. He gives the example of the small settlement of Broad Channel in New York. Families have lived there since the 1920s. They swim, they fish, they have a great view of lower Manhattan. Come hell or high water, the residents are not going to leave their homes. But high water it will be. Low-lying Broad Channel was one of the most heavily damaged areas of the city when Hurricane Sandy hit in 2012 and is swamped regularly by tidal flooding and storm surges that will only get worse.

“But they love where they live and the whole notion of getting up and going somewhere else is very hard,” says Goodell from his home in upstate New York. “Even people who understand climate change still think sea-level rise is a slow, gradual thing and they can build a seawall that will be fine for X number of years and this is a remedy for the problem.” It’s not.

Jeff Goodell.

Half a planet away, on the West Coast of New Zealand, the small community of Punakaiki has forked out close to $2 million to build a seawall. At a public meeting, recalls West Coast Regional Council chief executive Mike Meehan, a question from the floor asked when residents should stop investing in the seawall and look at moving on. It did not go down well. A motion was put forward never to raise the issue again. It was approved 39 to one.

“When you start investing [ratepayers’] money in protection works, it becomes quite difficult to have a productive long-term conversation,” says Meehan. “This stuff’s not easy. It’s hard, but it is something the country and the regions have to grapple with.”

In grappling with sea-level rise, Goodell pulls no punches. In 2013, he entitled his article on low-lying Florida an unsubtle “Goodbye Miami”. This year, in the wake of Hurricane Michael’s 4m storm surge, he wrote a story called “What’s Another Way to Say ‘We’re F-cked’?”.

“No matter what we do with carbon emissions, no matter how many solar panels we put on our house and what cool stuff Elon Musk designs,” he says, “we still have a significant amount of sea-level rise built into the system. There is a notion we can stop this. We can’t.”

In The Water Will Come, he says sea-level rise could reach 1.8m or more by the end of the century, the result of a warming atmosphere, thermal expansion of the oceans, melting glaciers and gravitational “fingerprinting” – by which water is pushed into the Southern Hemisphere from melting ice sheets in Greenland and into the Northern Hemisphere from Antarctica.

Tourists negotiate floodwaters in Venice at the Piazza San Marco, after storms last month. Photo/Getty Images

He takes us to the flooded Piazza San Marco in Venice (storms last week turned the piazza into a lake and left three-quarters of Venice submerged), to the slums of Lagos where 200,000 squatters live on a lagoon in houses built on stilts and to Lower Manhattan, where Hurricane Sandy carved a calamitous path, drowning streets under nearly 3m of water.

He talks to owners of beachfront homes in Florida deliberating about when to dump their investment on the real-estate market. He asks Miami developer Jorge Pérez whether he is worried about sea-level rise. Not at all. “Besides,” Pérez adds, “by that time, I’ll be dead, so what does it matter?” And he interviews Tony de Brum, Foreign Minister of the drowning Marshall Islands. “For us, the end has already begun,” de Brum says. “The question is, what are we – and what is the world – going to do about it?”

Those countries that can afford it are fighting back. New York is building the Big U, a multimillion dollar barrier system to protect the high-value real estate in Manhattan. Venice has poured US$6 billion – and counting – into a huge submerged mobile barrier called Mose (Modulo Sperimentale Elettromeccanico). Miami Beach has raised roads, with some several feet higher than the buildings they run past. But some parts of the city now flood regularly even when it hasn’t rained – all it takes is a full moon, residents say. Miami “is kind of the poster child for a major city in big trouble”, Goodell says. Elsewhere, money is being poured into pumps, plantings and sea barriers, but putting our faith – and money – into large defence structures will not solve the problem, he says. “The idea that if we just figure out some invention to protect the coast – build a wall, hire the right engineer, spend a lot of money – we can fix this, that is one of the central myths of our time. You can’t hire a Dutch engineer and send them around the world and say, fix it all.”

Hoboken, New Jersey, in October 2012. Photo/Getty Images

The future is already here

There is no Dutch engineer on hand to fix Haumoana, just south of Napier. Two months ago, waves pounded rock barriers and seawalls meant to protect the 21 houses stretching along the waterfront. Last winter, a huge swell washed away 2m of coastline. Down at the corner, the sea is inching closer to the water supply, power lines and the road itself. In neighbouring Clifton, two decades of north-east storms have shrunk the local motor camp by 50 campsites.

A new cross-council strategy recommends a combination of “re-nourishment” (building up the sand/gravel levels on the beach), more groynes and more breakwaters. That is for the short term. Looking out 50-100 years, it suggests “managed retreat” – in other words, pack up and leave.

“Yes, there has been erosion here,” says Keith Newman, spokesman for the Walking on Water lobby group, “but let’s protect what we have. Some of that 21 may well have to go, but we have to think of quality of life [and] access for people to come and see all the beauty and wonder of Cape Kidnappers. We have lagoons out here, birdlife – do we let those go? We have reserves out here – do they have a value? Can we afford the future? That is the question.”

Back on the West Coast of the South Island, the small coastal settlements of Granity, Ngākawau and Hector have been battered by winter storms that erode the beach, damage buildings and send waves crashing over fences and walls. Earlier this year, ex-tropical cyclones Fehi and Gita hammered this narrow stretch of land, taking chunks off State Highway 6 and saturating homes.

Advice given by the National Institute of Water and Atmospheric Research (Niwa) includes more coastal defences, a backstop of gabion baskets and “aggressive replanting” to buy some time. The safest strategy in the long term, it says, “remains to relocate offsite”.

Built on the soft, silty soils of a former wetland, South Dunedin, on the coastal edge of Otago Peninsula, has long been fighting the sea. Almost 2700 homes are less than 0.5m above sea level. In places, the water table sits as little as 0.3m below ground. As the sea level rises – which it has done by about 0.2m over the past century – it pushes the groundwater up towards the houses.

Neville Peat. Photo/Mary Hammonds

“South Dunedin is [our own] poster child for climate change,” says writer and former councillor Neville Peat from his home in Broad Bay, on Otago Peninsula. “Not so much from incursion by the sea but from the pressure of the rising sea on groundwater. But any major action is totally unaffordable for South Dunedin. Keep mitigating or retreat? Councils are always reluctant to commit themselves to a major plan when there’s no authorised model.”

None of Haumoana, Granity or South Dunedin want to be seen as the desperate face of climate change. They are picturesque areas, close to the sea, offering affordable houses and a strong sense of community. And they are not alone.

In his new book, The Invading Sea, Peat takes us on a nationwide tour of cities and settlements forced to face the watery impact of climate change, from Tamaki Drive in Auckland and Mokau sandspit in Taranaki to low-lying areas in Kāpiti, Lower Hutt, Nelson, Tasman, Canterbury and Ōamaru.

We are a maritime nation. Our coastline stretches 19,800km. Two-thirds of us live within 5km of the sea; 12 of our 15 largest towns and cities are coastal. But 80% of our coastline is eroding at anywhere between a few centimetres to about 10m a year. In the past century, says Peat, the sea level around New Zealand has risen by up to 20cm. Under present projections, it is expected to rise a further 30-100cm this century, inevitably bringing more floods, more erosion and more disruption.

And a lot more costs. A 2015 report from former Parliamentary Commissioner for the Environment Jan Wright estimates at least 43,683 homes, 68,000 buildings, 2000km of road, five airports and 46km of railways are within 1.5m of the current average high tide in spring. Total replacement cost for buildings: $19 billion.

The options, Tim Naish, director of the Antarctic Research Centre at Victoria University of Wellington, told the Listener earlier this year are brutally few. “You can protect, defend if the assets are worth defending – I suspect Auckland will defend parts of its coastline, Wellington will, New York is planning to – or you can retreat, which comes with massive disruption and social and economic issues.”

State Highway 1 at Paekākāriki after a storm last February. Photo/NZ Transport

Slow to adapt

But these issues, some say, are not getting the attention they desperately deserve. There is no doubt efforts are being made to mitigate New Zealand’s contribution to global warming. The Government is committed to a net carbon zero New Zealand by 2050 and a planned independent Climate Commission to guide the country through that process. Already we are set to amend our emissions-trading scheme, plant an initial 500 million trees and establish a Green Investment Fund. But in adapting to current and future risks of sea-level rise, we have been slower to act. According to a 2017 report by Motu Economic and Public Policy Research, much of the climate change-related economic research to date has been on developing market mechanisms to promote mitigation. “There has been less analysis of the economic impact of climate change or exploration of potential economic adaptations to climate change.”

Climate Change Minister James Shaw agrees. A nationwide risk assessment is due to start early next year – “but [adaptation] has been below the radar. It hasn’t had the attention emissions-reduction effort has had.”

Local councils have been left to carry the can. Under resource management legislation, councils are expected to avoid and reduce risk from coastal hazards. But many councils are hampered by inadequate land information, insufficient funds and different planning timeframes.

“If you think of sea level as a slow-moving earthquake, you want to respond to that before it becomes catastrophic,” says Dave Cull, Dunedin City Mayor and president of Local Government New Zealand (LGNZ). Every $1 spent on risk reduction saves at least $3 in future disaster cost, an LGNZ report says, but local government still won’t have the resources to deal with it, says Cull. “Some smaller councils don’t even have the resources to appropriately identify what their risks might be – we know.”

Judy Lawrence, co-chair of the Government-appointed Climate Change Adaptation Technical Working Group, says councils are pulling their hair out trying to deal with different bits of unaligned legislation, while also trying to appease developers and homeowners – all within a three-year electoral cycle not conducive to long-term planning.

“Often, all the emphasis goes on the Granitys and the Haumoanas where it is all happening now and there is an enormous kneejerk reaction to fix their problem by putting in a structure,” she says. “But that is not dealing with events before they happen and in some respects that money can reward unsustainable practices – frankly, those structures are not going to last the distance, not over the long term.”

Back in Hawke’s Bay, the local regional and Napier and Hastings councils have been working with communities and iwi to prepare a joint long-term coastal hazards strategy. This is a version of the so-called “adaptive pathways” approach recommended in a recent guidance document for local government – a broad-based, strategy-setting process that identifies different potential future scenarios and involves input from entire communities, not just those who live on the coast.

“Because it is all of our problem,” says Peter Beaven, chairman of a joint committee of Hawke’s Bay councils. “People who live further in come to the coast to go fishing, whitebaiting, walk the tracks, enjoy the beach. Everyone enjoys the coastline of this country so everyone is going to have to be involved in a solution.”

For homeowners, Keith Newman says, that conversation is vital. “If you are not confident councils are supporting you, you do not invest in your property, you don’t do house repairs. If councils can work together with people who have creative ideas, we can say, ‘What can we do, what are the costs, what can the community sustain?’ Then, I think, there is hope and confidence.”

High seas threaten beachside properties at Haumoana in July 2017. Photo/Tim Whittaker

How will we pay?

But adaptation also needs money, and although private investors have been quick to recognise the potential revenue stream from new innovations for mitigation, says Goodell, “there is not a lot of money to be made in adaption”.

“You have three options,” Shaw says. “Do nothing and ultimately that will get expensive; introduce an engineering solution such as pumps and seawalls and that is expensive; or move, and that is expensive. So there is a financing question here, no doubt. The country has to appropriately share risk across the property owner, local government, central government, the insurance industry and banks – and do that without creating moral hazard. If we create a system that encourages people to keep doing what they have always done because they know there will be a bailout at the end of it, then we will make the situation worse, not better.”

How we adapt to climate change, says National Party spokesman Todd Muller, is going to be the climate change story of the next 10-30 years. But the Government’s plan to limit new prospecting, exploration and mining permits ignores the role of natural gas as a replacement and transitional fuel for coal, particularly in developing countries to which we could export gas, he says. “If climate advice is saying we need to limit our emissions to constrain warming to less than 2°C, a critical part of that is the transition from coal to lesser-emitting energy sources.”

He says New Zealand is looking to mitigate its greenhouse-gas emissions profile “but we have to be honest and say, ‘What happens if the rest of the world doesn’t move at the pace that is required, and the sea level does rise and the coastal erosion does occur and our infrastructure gets impacted?’

Do we need to retreat? Subsequent to that is the far more challenging conversation which is, ‘How do we fairly pay for that retreat?’”

As it stands, areas with a large ratepayer base are finding ways to divert funds into groynes, seawalls and stopbanks, or strategies for removing at-risk areas from future development. But asking a small coastal town such as Broad Channel in the US or Granity on the West Coast to stump up a lot of money for protection work is a hard call. As Goodell says, climate change will hit the poor and vulnerable hard. “The social-justice issues that arise around adaption are huge. Whether it is government money or philanthropy or corporations – whatever pot of money you want to define – there is only so much. Then there is the question of who gets protected and who doesn’t. These issues are just going to grow.”

Bridging the funding gap

In this country, LGNZ is proposing a new local government agency to collect data and coordinate resources to help local authorities reduce coastal hazard risk. Already, Hawke’s Bay is setting up a ratepayer-based coastal-hazard fund to be used to shore up public assets. Elsewhere, homeowners are digging into their own pockets to barricade themselves against the hungry seas with walls and trenches.

To fill the funding gap, there have been calls for a coastal erosion and flooding equivalent of the Earthquake Commission, but Lawrence is not convinced. As she says, EQC kicks in after the event. Rather, she and Victoria University professor of public policy Jonathan Boston recommend a climate change adaptation fund similar to the Superannuation Fund, with contributions from property owners, councils, central government and industry, with a mandate to fund, part-fund or co-fund adaptation-related costs. A potential source for pre-funding, they write, could be revenue generated from an additional levy on fossil fuels, “with the pooled funds invested and then drawn down progressively later in the century”.

Venice after last month's storms. Photo/Getty Images

The inevitable retreat

But all the expensive structures and pumps and land-restoration programmes will not avert the need in some areas for managed retreat to remove houses and infrastructure from danger and to help nature build up its own defence systems. Although 20-90% of the world’s coastal wetlands – effective in filtering pollutants, storing carbon dioxide and protecting communities from storms – are under threat from coastal inundation, a recent study reported in Nature shows rising seas also carry sediment that can allow the coastal fringes to survive, as long as the wetlands can expand inland. As the authors say, for wetland areas this entails moving seawalls, rerouting coastal roads, giving up coastal agriculture “and sacrificing seaside real estate”.

De facto retreats have been staged. In Matatā in the Bay of Plenty, the council is looking to remove existing land-use rights on 45 at-risk properties; in Tasman, a new “residential closed zone” on low-lying land between Mapua and Ruby Bay has banned further subdivision, prohibited land filling and drawn a halt to new habitable buildings, extensions and replacements of existing buildings.

In Christchurch, the post-earthquake red-zoning experience created a precedent for the mass removal of whole neighbourhoods. As Mayor Lianne Dalziel says, “We managed to mimic the anticipated impacts of climate change in less than 45 seconds,” but the wholesale clearance of more than 7000 homes was funded largely by the Government through the Canterbury Earthquake Recovery Authority and insurance.

Affordable insurance

Outside the emergency provisions of a major earthquake, a large-scale managed retreat will be costly, but as Jan Wright stated in 2015, “the alternative to managing an inevitable retreat will be leaving people living in homes that become uninsurable”.

Insurance, of course, covers only unforeseen and accidental events. There is nothing unforeseen or accidental about sea-level rise, says Tim Grafton, head of the Insurance Council of New Zealand. But even ongoing flooding claims will provoke a reaction from insurers.

Already, some properties in Northland are not covered for floods. Following a rash of post-earthquake floods in Flockton Basin, in Christchurch, homeowners faced an insurance excess of $10,000 per flood before the council undertook a $48 million flood-mitigation programme. “That is where it starts to rub,” Grafton says. “Frequent flooding, frequent damage, will lead to higher excesses and/or higher premiums and potentially further downstream exclusions of cover for certain events. We have to focus on adaption or risk reduction to enable insurance to remain available and affordable to people.”

Recurring events such as flooding also raise questions around moral hazard – should people who live on higher and safer ground pay for people who live in flood-prone areas? Should those who bought an at-risk property before any discussions about climate change were raised, asks Grafton, face the same limitation as those who chose to buy into areas with full knowledge of the risks?

As Goodell says, the story of sea- level rise is not a happy one. Nor is it his role to spin the story to give people hope – a weird burden, he says, to put on climate writers. And what is needed is not hope but “courage in the sense of embracing change, thinking differently about our world”.

Although there will be a lot of “loss and wreckage”, he says, already architects and planners are looking at a range of long-term innovative solutions to allow us to live better with water. “A lot of our economic thinking is about short-term returns, about how we make money today. In the US, [President] Trump is all about mining the present at the expense of the future. But that is driving a lot of young people to think differently about how we measure success and progress in our world. I think it is part of a large social and cultural change that will accelerate as climate change accelerates.”

Bronwyn Hayward, a lead author of the report.

“We have only a dozen years” 

The Intergovernmental Panel on Climate Change (IPCC) special report, Global Warming of 1.5°C, marks the end of “magical thinking” about climate change, says University of Canterbury political scientist Bronwyn Hayward, one of the lead authors of the October report. Where the Paris climate agreement was gunning for a 2°C cap on global warming by the end of the century, this report warns 2°C is half a degree too far, and we only have a dozen or so years to bring warming under control.

That half a degree makes a difference. At 1.5°C instead of 2°C, global sea-level rise by 2100 will be about 10cm less, potentially stopping a “disproportionately rapid evacuation” of people and reducing the number exposed to the risks of rising seas by 10 million. Beyond 1.5°C, it says, the risks of droughts, floods, extreme heat and poverty will worsen for hundreds of millions of people.

“Frankly, we’ve delivered a message to the governments,” IPCC co-chair Jim Skea said at a press event. “It’s now their responsibility … to decide whether they can act on it.”

Or not. US President Donald Trump has resiled from the view climate change is a hoax, but nevertheless withdrew the US from the Paris agreement. Brazil’s newly elected president, Jair Bolsonaro, has threatened to open the Amazon rainforest to agribusiness. Australia’s Energy Minister, Angus Taylor, has said he has no plans to take coal out of the country’s energy mix, telling the ABC his Government would “not be distracted from our goal of lowering power prices for Australian households and small businesses”.

This is in response to what many have described as a conservative reading of future risk. Nobel Peace Prize winning glaciologist and climate scientist Richard Alley says with ice-sheet collapse in West Antarctica and ice loss from Greenland, East Antarctica and other sources, sea-level rise could reach 4-6m. “For the most respected ice scientist in the world to say that,” says climate change writer Jeff Goodell, “shows what scientists think about how bad this could get and how quickly.”

This article was first published in the November 17, 2018 issue of the New Zealand Listener.