Pulling people and property out of climate change’s line of fire isn’t a probability in New Zealand’s most vulnerable communities, but an inevitability. And in some locations, it’s already happened. University of Waikato environmental planning lecturer Dr Christina Hanna talked to Herald science reporter Jamie Morton.
What is managed retreat, and why are we hearing more about it now?
Managed retreat means relocating people, assets, activities, and taonga, where appropriate, from dangerous locations.
It can also involve ecosystem migration or restoration to mitigate environmental harm and build adaptive capacity via natural defences.
While the term “retreat” may be associated with “defeat”, colleagues and I frame it as the remaking of space, to remedy unsustainable land use patterns and activities.
Managed retreats can be applied across time and space, from residential, commercial or recreational activities to farming and forestry land uses, among others.
Put simply, managed retreats represent land-use change.
Buyouts, land swaps, re-building restrictions, zoning and land use controls, time-limited resource consents and compulsory property acquisition are just some of the ways managed retreats can occur.
Delivering managed retreats that are sensitive to the dislocation of people from their homes, livelihoods, and place-based ties, is challenging.
People, communities and environments have different values and needs and will face different losses, meaning locally tailored approaches are necessary.
We’re hearing more about managed retreat as people are experiencing more severe, recurring, and compounding impacts of climate change, to the point where some are now asking to be relocated.
In addition, Aotearoa has a legacy of risky settlements traversing fault lines, steep slopes and flood plains, and contemporary planning decisions often resort to “mitigating” rather than “avoiding” risk due to competing pressures.
How and where has it been used in the past, here and overseas?
Globally, there are historic trends of people relocating in the face of harm, but managed retreat is a deliberate, co-ordinated strategy to reduce risk exposure and make space for nature.
Ideally, managed retreat occurs before disaster strikes, but without policy frameworks in place, it is often undertaken reactively.
A study published in Nature Climate Change examined recent managed retreats, which have relocated approximately 1.3 million people globally.
Case studies include indigenous communities in Alaska facing melting permafrost, land swaps for flood ravaged properties in Grantham, Australia and the Residential Red Zones in Aotearoa, to name a few.
In terms of the history of Aotearoa, Māori have long demonstrated practices which resonate with the philosophy of managed retreats, via cultural restriction or avoidance of certain activities, tikanga based resource management, and adaptive re-settlement.
An example from 1850 describes a Māori chief relocating the hapū from Pākowhai pā to Waipatu following a significant flood.
Since colonisation however, much of the response to disasters in Aotearoa could be categorised as “unmanaged retreat” due to the unplanned and often unassisted nature of human mobility.
Recent policy experiments such as in Waitakere (Project Twin Streams) and The Hutt City (Riverlink) demonstrate more strategic approaches.
We are yet to see co-operative managed retreats where people and communities are embedded in the retreat strategy design, decision-making and delivery.
How likely is it that we’ll begin to see cases of it within the next decade? And could even the recovery from Gabrielle bring our first wave of managed retreat?
We are already seeing managed retreats across Aotearoa, where it has been incentivised, enforced, or planned, such as in the Canterbury Red Zones, Matatā and Haumoana.
The first few waves of managed retreats have already begun, and future managed retreats must learn from past experience.
Managed retreat has been often been called a last resort - or the “nuclear option” in one case - but in many instances around our coastlines, is it an inevitability?
Managed retreat is inevitable for some communities, public places and assets, and possible for cultural and heritage sites too. It isn’t limited to the coastal environment.
Experts can’t tell you exactly when and where it will occur across the nation yet because the equation is too complex, too human.
We are talking about people’s homes, marae, papakāinga, urupā, livelihoods, recreational reserves or beach access, ecosystems, businesses and farms.
The decisions and processes to reform our local spaces and places are multi-faceted, requiring collaborative input from mātauranga Māori, western science, local knowledge, spatial and land use planning, and infrastructure providers.
Importantly in Aotearoa, rights to tino-rangatiratanga (self-determination) for Māori land and taonga must be upheld.
What do we know - and what don’t we - about New Zealand’s exposure to climate impacts and where managed retreat may have to be used? For instance, we’ve seen some national risk assessments already, but how much more work needs to be done to build the picture we need?
It’s important to recognise that protection and accommodation measures can mitigate some risk.
However, managed retreat may be necessary when residual risk is intolerable, risk reduction measures are not viable, or the adverse effects of intervention or inaction are unacceptable or irreversible.
The example of Matatā demonstrates one decision, where the risk to human life was high and could not be mitigated by debris flow nets or warning systems for the properties.
This example also demonstrates the granularity of the information required to have these discussions.
Determining what “high” or “intolerable” risk means in local contexts is central to this issue and a key piece of the Climate Adaptation Act.
What is the relationship between managed retreat and insurance or credit retreat? And, in New Zealand, can we expect the latter to precede or precipitate the former?
As [Climate Sigma managing director] Belinda Storey’s research has demonstrated, insurers have an easy exit route when risk/s becomes too high due to annual contract renewals.
We cannot rely on private insurance payouts to support managed retreat, except in post-disaster situations, if they haven’t already retreated.
Reactive retreat risks lives, ecosystems and socio-economic damage, and insurance payouts can entrench unsafe rebuilding.
Insurance retreat may send a market signal to future property owners but it will leave many vulnerable, financially trapped in a dangerous place.
Storey warns that in our four largest cities, full insurance retreat is likely to occur for at least 10,000 properties by 2050 as a result of sea level rise.
What legislative frameworks does the Government currently have in place to facilitate managed retreat - and what important work is being carried out right now?
At present, managed retreats are risky due to the lack of fit-for-purpose legislation and funding resources to enable effective and equitable outcomes.
The proposed Climate Adaptation Act - and its intersections with the National Built Environment and Strategic Planning Bills - aims to address the technical, legal and financial issues associated with managed retreat.
What are some of the most challenging or contentious issues that come with managed retreat - particularly around how it should be paid for?
Managed retreats spark many difficult issues regarding who seeks to be or should be relocated, why, when, how, where to, and at whose cost?
Its delivery is multifaceted, from the necessary risk and cultural impact assessments, spatial and land use planning requirements, options’ analysis and funding decisions, to the asset removal and recycling operations, restoration, monitoring and legal protections required.
In terms of funding, a recent working paper released by EDS is considering (and welcoming feedback on) these important issues.
It asks what principles should underscore the legislation, whether we should leave people to suffer losses or come together as a nation to assist those who are most affected, and whether the managed retreat framework should be transformative, delivering improved outcomes for people and nature?
To me, the answer to the latter is clear. There must be opportunities for transformative change.
Managed retreats require us to reimagine our local spaces, to navigate loss and find opportunities to improve social, cultural and environmental wellbeing among change.
- Dr Christina Hanna acknowledges research colleagues Professor Iain White, Professor Bruce Glavovic and Dr Raven Cretney who have collaboratively contributed to research on managed retreat in Aotearoa. Hanna is funded by the Aotearoa New Zealand Government National Science Challenge: Resilience to Nature’s Challenges – Kia manawaroa – Ngā Ākina o Te Ao Tūroa. Hanna also receives funding from the Ministry of Business, Innovation and Employment’s Endeavour Fund to research issues connected to flood risk mapping and better decision-making.