The land of the rising sea

By Ruth Laugesen In Commentary

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As he plans his retirement beach house at Waikanae, climate change expert Martin Manning keeps a wary eye on the future. His chosen site is 1km from the shoreline, and a hefty 14m above sea level.

Is he concerned about rising seas? “I have these things in the back of my mind,” says Professor Manning, director of climate change at Victoria University.

With little hope right now of decisive action internationally to slash greenhouse-gas emissions, an increasing number of voices are saying we must begin preparing defences against a more volatile climate, more storms, more rain, more drought and higher seas. And change may come faster than we expect.

The good news for New Zealand is we should be spared some of the extremes of temperature that will affect continental land masses. But we still have much to contend with.

New Zealand lives by the sea. About 65% of our population and major infrastructure is within 5km of the ocean. Of our 15 largest centres, a dozen hug the coast. Road and rail run near the sea: 160km of rail is 5m or less above sea level, as are 222km of state highways and 2000km of local roads. Auckland’s downtown and Wellington’s CBD are close to the sea, and the airports of Auckland, Wellington and Dunedin are low lying.

Around the world, extreme weather events have already become commonplace – last year floods inundated a fifth of Pakistan and a heatwave triggered wildfires and destroyed crops in Russia, and earlier this year Queensland suffered extraordinary floods that breached the state’s defences.

We are now entering the second era of climate change, says American journalist Mark Hertsgaard, and are starting to feel some of the force of what has long been predicted.

In his book Hot: Living Through the Next 50 Years on Earth, he argues this means we need to start preparing for higher seas and wilder, hotter weather now.

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“This is no longer about future generations, this is about today. Not only has it already begun, but it is bound to get worse, even if we do everything right. We have got to prepare,” says Hertsgaard, on the phone from his home in San Francisco.

Sea-level rise may come faster than first thought. Scientific estimates on how high the sea might rise by 2100 still contain much guesswork, but they have gone up and up – doubling in the past four years (see box next page). Some scenarios warn of seas rising by more than 2m by 2100.

And the scientists tell us even if all carbon dioxide emissions were to cease tomorrow, decades of unavoidable climate change, ice melt and sea-level rise are already built into the climate system before it stabilises again.

So, what sort of preparations are being made? Leading the pack internationally on preparing for climate change is the Netherlands, which is finely attuned to the threat of the sea. The Dutch were shocked into action after seeing the devastating force of Hurricane Katrina in 2005 and the flooding of New Orleans. It reawakened a historic dread of the sea in this low-lying country, which launched a 200-year plan for climate change.

The plan is to prepare for a sea-level rise of 0.65-1.3m by 2100, and 2-4m by 2200. The Dutch are allocating huge sums of money, and are overruling some vigorous local opposition to new “sacrifice zones” where settlement will be abandoned. Flood protection is being increased by a factor of 10, with an annual cost of up to $450 per person, and fresh water supplies are being secured.

A new Delta Fund will be fed at least €1 billion a year from 2020 to pay for the works. On the outskirts of the city of Nijmegen, two sacrifice zones that will be allowed to flood have been drawn up. What is striking, says Hertsgaard, is the unity behind this national plan, the lack of squabbling.

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In the US state of Washington, King County has made long-term decisions to pour money into stronger levees to cope with increased flooding. Again it has taken tenacity to win support for hard decisions. King County executive Ron Sims fought hard for an expensive new facility that recycles wastewater for use in irrigation and other non-household purposes to help ensure there will be enough water in the dry times ahead. In every department in the county government, officials are told to “ask the climate question”, checking what conditions the county will face in 2050 and figuring out what work needs to start now.

In New York, a city taskforce has come up with two projections for sea-level rise: one for 0.3-0.6m by 2080, and a second for a rapid ice-melt scenario of 1-1.4m by 2080. Detailed land elevation maps are being drawn up to document flood-prone areas.

Does all this mean giving up on trying to prevent climate change? Absolutely not, says Hertsgaard. “The traditional understanding of climate change is that we’ve got to go solar or wind and stop burning so much oil and coal. That’s obviously still true, and more true than ever, but you’ve also got to prepare for these impacts that are not going to go away.”

And if we don’t cut emissions, even more extreme scenarios loom. What is clear, says Hertsgaard, is adapting is not just about having money. The societies that do best will be the ones that can agree on a plan.

How well is New Zealand facing up to this second era of climate change? According to Local Government New Zealand president Lawrence Yule, local authorities have been left with the job by central government and they feel somewhat abandoned.

“My overall feeling is that at the moment this is seen as too hard, no one wants to take a lead on it and we’re in a policy vacuum on a national basis,” says Yule. Some councils are working hard on the issue, but progress is patchy. At one recent meeting of mayors, “two of the more vocal mayors said climate change is a lot of rubbish and we shouldn’t get drawn into it”. So far, Auckland Council has done little, but work is under way in Wellington, Christ­church, Dunedin, Hawke’s Bay, Tauranga and Kapiti.

Manning, a leader of a major government-funded research project on adaptation to climate change, says some councils are active and others say, “Oh no, we’ve got much more important things to do.” “Something our research is flushing out is that the big problem in adapting to climate change is to overcome this sense of inertia.”

Manning says the Chinese decided in 2008 to move all roads to at least 3m above sea level. Now they are looking at their big cities – which ones to build big sea walls around, and which to slowly relocate over the next 50 years.

China has a big advantage in thinking ahead. “China has a 30-year plan. Most Western countries can’t think past the next election.” He says big spending to protect major investments makes economic sense. Big sea walls could be built to protect the Wellington and Auckland CBDs, and the major airports would also need to be defended.

Some decisions in this second era will be easier to make – who could quibble over the need for new drainage and storm­water systems to cope with heavier rainfall, or for new roads to be built at higher elevations? But other fights will be bitter.

Most bitter of all will be the arguments over when to defend the coastline and when to let the sea come in. At selected locations around the country, councils are mapping coastal hazard zones they believe will be at risk from inundation, erosion and storm surges over the next 50 to 100 years.

In Hawke’s Bay new developments are being restricted in hazard zones; in Kapiti and Tauranga, any new housing in hazard zones needs to be relocatable. And the Tasman District Council notified a radical plan change in February for Mapua and Ruby Bay, banning further subdivision on the flat coastal area and redirecting development to the hillier areas.

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Some of the at-risk beachfront land “is some of the most highly valued real estate you’ll find”, says Yule. Councils are facing fierce fights in the Environment Court from developers who want to continue their long profitable burst of coastal development. Developers “try to challenge some of the scientific information, or put up people to say that climate change isn’t happening”.

Until now, local authorities have generally seen it as their mission to hold the line against the sea. But with higher sea levels and stronger storm surges, New Zealand may have to resort to Dutch-style “sacrifice zones” of residential land given up to the waves.

Existing settlement patterns will have to change, says Yule. Environment Waikato has carried out a research project on “managed retreat”, in which vulnerable land would be abandoned. Some 920 properties in the Coromandel have been identified as at risk from coastal erosion over the next 100 years, properties worth about $850 million in 2004 and much more now. Two-thirds of these are already at risk. In the Bay of Plenty, 1000 properties have been classified as being in coastal hazard zones, and again two-thirds are already at risk.

The report concludes that property owners would have to be forced off their land, as they rarely submit voluntarily. Whether and how they should be compensated is unclear.

In Hawke’s Bay, which is recovering from violent storms and floods at the end of April, what is happening at the beachside settlement of Haumoana is a forewarning of how reluctant New Zealand coastal dwellers are to offer up sacrifices to the sea. The tiny settlement, where homes are already tumbling into the ocean, suffers from erosion that dates back to the 1930s as a result of long-term shifts in the coastline. It was battered again in the recent storms.

Yule, who is also the Hastings Mayor, says the county council offered to buy locals out 20 years ago. Of 36 properties, the owners of only three took up the offer. “The rest are still there and are slowly being eroded away.”

Now Yule’s council and the Hawke’s Bay Regional Council want to remove and relocate up to 40 homes in Hau­moana and nearby Te Awanga. “It is particularly unpopular, nobody wants to think about it,” says Yule. Locals are fighting back, and calling for millions to be spent on defences against the sea.

The awkward question that looms behind all this is how high sea levels will go. The disconcerting answer from scientists is they can’t give a definite number. What they can say is that the best estimates are climbing, not falling.

Local authorities are working to a sea-level rise laid out in Ministry for the Environment guidance, which suggests a base sea-level rise of 0.5m by 2100, but that the consequences of 0.8m or more should be considered. But in practice, says Manning, 0.5m is seen as the golden number and the higher end of the range is ignored.

“The chances of sea-level rise being less than 1m by 2100 are starting to look pretty slim, frankly,” says Manning, who was a senior player in the last report of the Intergovernmental Panel on Climate Change. In New South Wales, planning authorities are working to a minimum sea-level rise of 0.9m by 2100, in Queensland it’s 0.8m and in California it’s 1-1.4m.

Should the Ministry for the Environment raise its baseline guidance of 0.5m sea-level rise by 2100? Another of New Zealand’s most senior climate scientists is Niwa’s David Wratt, who has a senior role at the IPCC as it prepares for its 2013 report on the scientific consensus on climate change. He says the Ministry for the Environment guidance is a good start for now. He notes that 0.5m is only a starting point in the guideline, and it does urge consideration of the consequences of higher sea-level rises.

Doug Ramsay, who is leading Niwa’s work mapping coastal vulnerability to sea-level rise, says this is an issue he comes up against continually. “Developers, planners, they all want one number.” Surely that’s reasonable, isn’t it? “It is, but at present science can’t give you that. Certainly there’s information that suggests a 2m rise is the real maximum that could happen by 2100, but more realistically it’s 0.8m or 0.9m, that kind of number.”

Getty Images; Paul Taylor/Mark Mitchell/APN

No wonder local authorities are finding it too hard in many cases. Yule says in the face of scientific uncertainty, they need central government to step in and make a ruling on what number councils should be planning for.

“Councils around the country and developers are spending lots of money trying to deal with this issue without any national consistency. We would be better off with some national consistency, even if that is modified every 10 years as scientific data becomes available.”

Environment Minister Nick Smith seemed to agree in 2009, saying work would begin on a possible National Environmental Standard on sea-level rise. This would give legislative backing to councils when it came to defending their policies in the Environment Court. But when the Listener asked the Ministry for the Environment what had become of that work, the ministry said at this stage the standard is no longer being worked on.

When asked for his reaction, Yule said this was the first official confirmation he’d had that the work had stopped. “I’m disappointed. The longer we put off making some decisions on this type of issue, the more investment continues in vulnerable places. It’s one of those things everyone thinks is a bit hard because it affects a whole lot of real estate. I actually don’t think it’s too hard. At the moment there is no decision, and we’re just carrying on with existing settlement patterns.”

However, Smith said the Government “is still considering a National Environmental Standard on sea-level rise”.

“I appreciate it is difficult for councils to plan for sea-level rise where there is not 100% certainty. However, a National Environmental Standard or policy statement will not remove the scientific uncertainty. The 0.5-0.8m guidance is the best the Government can provide in the interim. We will consider advancing a more certain National Environmental Standard when we receive the latest IPCC [draft] assessment report next year.”

Smith said the Ministry for the Environment guidance did not need revision. “We accept there are scientific institutions whose views are that this is too low or too high, but believe it represents fair, balanced advice relative to the uncertainties and long time horizon.”

Martin Manning sympathises with the frustration many feel over the lack of certainty from scientists. But what is certain, he says, is we face real risks and we need to start planning for them, even though all the scientific information is not in yet. He and others say what is needed is a risk-management approach, in which expensive developments are moved well away from coastlines. A toilet block might be fine for a shore front, but a power station would not.

“Science is so committed to trying to understand everything before it says anything. And really, when you look at the rates of change that are going on and their seriousness, we have to take a slightly different line and be much more aligned with risk management.”

His proposed beach house is probably a perfect example of prudent risk management. Current scientific bets are the sea won’t rise 14m any century soon. But with such a big personal investment, Manning will sleep easier at night if he isn’t taking any chances.

“With the right approaches you can develop resilience to the changes. But you need to understand the changes can be serious, and they can sneak up on you.”

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