The first 2 months of 2023 brought unprecedented rainfall and flooding to the North Island of Aotearoa New Zealand, especially Tāmaki Makaurau, the Coromandel, Tairāwhiti and Hawke’s Bay. This has triggered a public health crisis and exacerbates the already unacceptable health burden experienced by Māori, Pasifika and other structurally oppressed communities. These storms show us how our climate pollution is driving severe weather, and that every action to recover must also be an action to prevent further devastating events. They also send a clear message that prevention means systemic decolonisation and restoration of Indigenous relationships with the land and waterways.

On 10 January, Cyclone Hale hit hard in the Northeast and was followed several weeks later by an unexpected and unprecedented rainstorm in Tāmaki Makaurau—parts of the city received 3 months’ average rainfall in a single day. This caused widespread damage to houses, businesses and vital infrastructure. Shortly after, ex-tropical Cyclone Gabrielle brought further record rains and devastation, especially to the east coast of the North Island. The worst-affected areas of Tairāwhiti and Hawke’s Bay experienced large-scale flooding, slips and destructive landslides, with damage often compounded by forestry debris. The floods were remarkable in the volume of rain that fell, the speed with which they occurred, the accompanying wind and uncertainty about the path of the water, leaving little time for early warnings or preparation. In total, there were 11 deaths from drowning and injuries, nearly 225,000 people lost power[[1]] and thousands were cut off from essential supplies, with many trapped in uninhabitable homes.

Health impacts

It is too soon to determine the full health losses, but it is likely they will be substantial. Previous research in Aotearoa demonstrated that with every heavy rainfall event comes a surge in hospital admissions for children with gastroenteritis.[[2]] Hawke’s Bay is already seeing an increase in cases of leptospirosis resulting from contact with flood waters on livestock farms.[[3]] In Napier, the wastewater treatment plant was severely damaged by silt, leaving it inoperable with untreated sewage being discharged to the sea. As a result, kaimoana has been dangerous to harvest and beach-swimming unsafe.  The current marine heatwave is not only driving storm severity, but also making the consequences worse, because enteric pathogens flourish in warmer waters.

Immediate effects on mental health are often hidden and underestimated. Prone as the East Coast is to catching the tail end of cyclones, residents there were already speaking of feeling “paranoid” about the safety of their families and homes whenever the rain falls, with this chronic level of fear and anxiety affecting their mental health. This is reflected in the research literature about the public health effects of flooding and sea level rise, where post-traumatic stress disorder and psychological effects are major features.[[4]] Studies of the longer-term effects of flood events like these are very rare and difficult to undertake, likely underestimating the mental and physical health effects. In a United Kingdom exception, more than half of the participants reported that they were experiencing physical and mental health effects attributable to flooding at 4 years following the initial event.[[5]]

Longer-term effects are to be expected with such widespread damage to housing and other buildings on top of an existing housing crisis. Not all affected buildings have yet been assessed, but by 2 March, 750 buildings had been condemned, while access to more than 3,500 was restricted by damage, and a further 4,600 had possible unseen damage making them unsafe.[[6]] Many of these are houses in areas where housing quality, availability and affordability are already significant public health issues, for example in Wairoa where over 150 houses were red- or yellow-stickered. For many of the lowest-income families, without insurance, returning to a yellow-stickered home and continuing to live in it as it gets mouldier are the only things they can do, despite serious long-term effects on health and safety.

Both short- and long-term effects on health disproportionately affect communities who already face structural disadvantage. Māori, Pasifika, disabled people, low-income households and those living in marginal housing are among those hit hardest by the recent floods and storms. These events also exacerbate inequities for rural communities, in particular the most remote Māori communities, where structural racism, socio-economic deprivation and rurality already intersect to compound health inequities.[[7]] Climate change is widely acknowledged as a threat multiplier, and is recognised by Indigenous peoples as an intensification of colonialism,[[8]] and the legacy of privilege and oppression can be clearly seen in the inequitable impacts of these events in Aotearoa.

What’s driving these extreme events?

These severe storms show us how climate change-related heating of oceans and air are making storms more frequent and more severe, especially when coupled with La Niña’s pattern of warmer oceans and tropical cyclones. In March, the World Weather Attribution group concluded that the very heavy rain associated with Cyclone Gabrielle was now four times more likely and that each storm now brings a third more rain on average than when the world’s weather was not affected by our climate pollution, and was 1.2°C cooler.[[9]]

It’s not just the weather, though. Coupled with climate change effects on storms and rainfall are the roles of geography and our land use choices. The North Island’s steep hillsides and exposed friable soils make it prone to slips and landslides. Its northern and eastern extremities are frequently in the paths of storms moving south out of the tropics. These risks are amplified by land use, especially the clearance of native forests to be replaced by high emissions livestock farming, and exotic plantation forests, as well as the extension of human settlements into low-lying river valleys and steep, exposed coastal areas.

These environmental transformations that have increased our susceptibility to flood events are a direct legacy of settler colonialism in Aotearoa.[[10]] The associated marginalisation of Indigenous knowledges and disruption of Māori relationships with the whenua has not only underpinned current risks, but further undermines our ability to prevent and manage worsening threats.

How should we respond?

Global inaction on climate change so far, including here in Aotearoa, means that adapting to the current level of warming is crucial. But adaptation is not just about engineering to protect current static living patterns: social and institutional responses need to work with dynamic land- and water-scapes, and revisit the framing and response to extreme weather. Centralising Māori conceptualisations can help us understand severe weather as dynamic parts of ecological cycles, with potential benefits for humans and the environment (e.g., improving the fertility of soils).[[10]]

This emphasises the importance of Indigenous worldviews, value systems and knowledges in developing healthy responses to climate change. However, agencies must go further than simply recognising mātauranga Māori; they must uphold the right to self-determination for tangata whenua, so that relationships with whenua can be restored and responsibilities such as kaitiakitanga fulfilled. Iwi- and hapū-led responses have been critical in protecting and supporting communities, both in the immediate period after these events and in the longer-term recovery. An important part of building resilience in future will be growing the capacity of iwi, hapū, marae and other Māori communities, and strengthening Tiriti-based partnerships and local participatory planning.

Cutting our emissions remains the best prevention measure. There is a real risk that attention and resources will now be diverted towards dealing with the escalating effects of the climate crisis, leaving emissions reduction a lower priority. Indeed, there have been explicit calls for such an approach in the aftermath of Cyclone Gabrielle.[[11]] However, this narrative is ill informed and dangerous. It is akin to furiously bailing water out of a sinking ship while doing nothing to fix the ever-expanding leak. “Business as usual” policies on climate change put the world on track to heat by 3 degrees or more above pre-industrial temperatures by 2100, roughly three times what has occurred so far.[[12]] The damage caused in New Zealand this year by super-charged storms and floods will be a pale version of what’s to come if we continue on our current path.

To be able to manage both mitigation and adaptation, we must reconceptualise climate action. While they are separated in national legislation and policy, they need to be integrated in implementation, avoiding tensions between them, as well as prioritising responses that address other social justice and health equity goals.

For instance, housing and land use planning requires transformation to tick all boxes for health equity, access, zero emissions and climate change adaptation. A fundamental shift is needed from a market-led approach to a systemic, integrated government- and community-led approach for the provision of healthy homes as a human right. Houses must be built in the right places for access and resilience to severe weather and incorporate zero carbon designs, energy sources and construction. For example, energy-efficient housing powered by subsidised local renewables (like roof-top solar and local wind) reduces emissions and helps address energy poverty, while also buffering against grid-level power outages during extreme weather events. Rural land use and agricultural reforms must also simultaneously reduce dependence on fossil fuels, improve resilience in the face of climate extremes and cut methane emissions.

Notably, many of these climate change mitigation-adaptation strategies have substantial benefits for health and wellbeing, for example due to improved freshwater quality, healthier diets, increased physical activity and healthier indoor environments. If designed in ways that are inclusive and just, with Te Tiriti at the centre, they can also make significant contributions to health equity.

Health professional training and support is also needed, particularly in rural areas, so that we can play our required roles: protecting public health during and in the aftermath of flooding; putting health equity and Te Tiriti at the heart of recovery; and advocating for integrated approaches to healthy, equitable climate action. A recent national survey exposed structural under-preparedness of rural general practices to respond to these role requirements, calling for capacity building and resourcing for both adaptation and mitigation.[[13]]

The recent superheated storms show us what a terrible race we are in to avoid catastrophic trajectories. They also show us that the current “bread-and-butter” political compromises on climate action ignore the uncompromising nature of climate physics, which isn’t waiting for another election. We now have to face up to the need for integrative responses to extreme weather, while also tackling the root causes of climate change. Colonial economic values, governance systems and living practices have driven the climate crisis and underpin our susceptibility to the ensuing storms. We must disinvest from these systems and instead centre Indigenous knowledges and restoration of relationships to address the fundamental causes of public health and ecological crises.

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