Zealand Climate Research Articles

Indigenous, ethnic, and racial diversity and climate justice: New Zealand’s climate adaptation policies and policy approaches

This research paper interrogates the extent to which indigenous, ethnic, and racial diversity is substantively integrated into climate justice discussions with a focus on New Zealand’s climate change adaptation policies. A qualitative research design is used, employing a documentary analysis and summative content analysis to scrutinise New Zealand climate change adaptation policies and their responsiveness to indigenous, ethnic and racial diversity within the ambit of climate justice. This study aims to measure the extent to which these policies promote inclusive and equitable climate adaptation outcomes. This study makes a significant contribution to the nuanced understanding of climate justice research, particularly regarding indigenous and ethnic minority communities. The study is expected to contribute to the existing knowledge base and inform the formulation of inclusive policies that integrate the diverse perspectives of these communities into climate adaptation and policy-making processes. The research findings highlight existing gaps and emphasise the importance of incorporating indigenous, ethnic, and racial diversity into policy development and implementation. The aim is to shape climate adaptation strategies that are representative of aware of insights from various communities in contemporary cities.

Moving to a new normal: Analysis of shifting climate normals in New Zealand

AbstractNew Zealand's National Institute of Water and Atmospheric Research publishes climate normals for New Zealand that are used for reporting the regional state of the climate, climate extremes and variability. Temperature and precipitation patterns are affected by both anthropogenic climate change and natural climate variability which in turn affect the climatological normal values calculated every decade. This study investigates how New Zealand's normals for temperature and precipitation have shifted over time at the national, regional and seasonal scales from the 1941–1970 period to the 1991–2020 period. Contrary to WMO recommendations, but aligned with many other countries, New Zealand's climate normals have traditionally not undergone homogenisation. The impact of introducing some homogenisation in the latest 1991–2020 normals, in contrast to historical non‐homogenized station normals, has been assessed using a new homogenized “Seventeen‐Station” temperature series from 1941 to 2020. We demonstrate that interpolating sparse non‐homogenized normals spatially to a grid can produce significant erroneous patterns and therefore undermine the accuracy of the conclusions drawn when using such normals. We find that the historical non‐homogenized temperature normals have a consistent negative bias in the long‐term trend at national, regional and seasonal scales. Our analysis of homogeneity tested precipitation showed consistent decreases at a national scale across all normal periods relative to the 1951–1980 precipitation normal. We also highlight how fixed period temperature and precipitation normals do not fully reflect the current state of a climate that is influenced by decadal variability and global warming. To derive normals fit for use in a changing climate it is suggested that automated methods for broad data homogenisation be developed along with alternative methods to derive normals that account for a non‐stationary climate.

Aotearoa New Zealand Climate and Environmental Journalists: Profiles, Practices, and Perspectives

This study investigates the profiles, practices, and perspectives of leading climate and environmental journalists from Aotearoa New Zealand. Based upon semi-structured interviews, this study discusses the state of national climate and environmental reportage, as well as possible and desired futures in the round, as responses to the rapidly emerging climate and biodiversity emergency. Within a comparatively small national media ecosystem, the interviews reveal a diversity of backgrounds and degrees of scientific expertise, a collegial relationship amongst the journalists, and a relatively high degree of autonomy in their respective newsrooms. The research notes the journalists believe climate and environmental reportage has increased in Aotearoa New Zealand in recent years although the level of coverage is still insufficient, and there are ongoing struggles to locate climate and environmental journalism within existing news frames. The interview discussion also explores features of reportage such as source relations, workload pressures, and audience engagement. This study explores how journalists negotiate their personal commitments to environmental change within the context of their professional practice. It also discusses the issue of advocacy reportage in climate and environmental journalism and possible critiques of existing journalistic practices and dominant news frames within the contexts of a climate and biodiversity emergency.

Predicting facial eczema risks in a changing New Zealand climate

Facial eczema is a major concern for New Zealand farmers due to its economic impact and animal welfare implications. The disease occurs when animals ingest sporidesmin, a mycotoxin produced by spores of the fungus Pseudopithomyces chartarum. Spore production is related to weather conditions; thus the incidence and severity of facial eczema varies between years, with thedisease commonly occurring from late summer through autumn in the North Island. We developed a simple model to estimate climatic suitability for P. chartarum sporulation and ran it using climate data for 2008-2021 to compare its estimates with spore counts from the same years. Model climatic suitability estimates had significant linear correlations with an index of exposure to spores derived from spore counts at both national and local scales. Model results were also consistent with a documented outbreak of facial eczema. Using predicted future climate data from the Hadley Centre Global Environment Model version 2 and two emissionsscenarios, the model suggested climatic suitability for P. chartarum sporulation will increase with time in many New Zealand regions, particularly in the southern North Island and eastern parts of the South Island. However, it could remain relatively static in some other areas, thus the degree of change in climatic suitability for P. chartarum sporulation is predicted to vary between New Zealand regions.

Assessing the economic implications of national climate change mitigation policies on cities: A CGE analysis of Auckland, New Zealand

Computable General Equilibrium (CGE) models have proven to be instrumental in the climate policy literature. Although their use at the sub-national level has increased, their application to assess the implications of national climate policies on cities is scarce due to the low availability of city-level economic and environmental data. Cities could play an instrumental role in the fight against climate change as they are home to more than half of the world population, generate more than 80% of global Gross Domestic Product (GDP) and are responsible for 75% of global greenhouse gas (GHG) emissions. National CGE assessments of climate policies overlooking cities could result in missing major opportunities to achieve ambitious reduction targets considering that cities are centres of innovation and wealth. Hence, the objective of this study is to fill that gap in the literature by developing and using a recursive dynamic, multi-regional CGE model to link a city's economy to the rest of the nation to assess the direct and indirect economic impacts from national GHG emissions reduction pathways. The city of Auckland, New Zealand (NZ) has been used as a case study due to the city's proactive climate mitigation plans. The model and scenarios used resemble the ones developed by the New Zealand Climate Change Commission (CCC) to inform national policy advise provided to the government. Additional scenarios were developed to incorporate Auckland's growth and climate strategies. The results showed that in contrast to the rest of New Zealand, the impacts on the Auckland economy are more pronounced as reflected by the more drastic percent changes (with respect to baseline) of the regional GDP (−6% for Auckland and −1% for NZ) and consumer welfare (−5% for Auckland and 1% for NZ). The more pronounced impacts on Auckland are due to the difference in profile emissions (e.g., urban versus rural sectors), fewer low-emission technological alternatives (e.g., rural technologies do not cater to urban sectors' needs), and indirect impacts from importing agricultural products with a higher price tag due to rising GHG prices. This study's contribution in the climate policy literature is to serve as evidence and precedent to carefully evaluate the nuances encountered in complex urban systems when developing national climate policies considering that the number of countries establishing legally binding reduction targets is continually increasing.

Assessing land suitability and spatial variability in lucerne yields across New Zealand

Lucerne (Medicago sativa L.) is a widely grown perennial legume worldwide which can provide high biomass and protein yields, biological N fixation, deep soil water extraction and a range of ecosystems services relevant to current and future agricultural systems. The potential to expand lucerne beyond its current cultivated areas in New Zealand, and its potential productivity across the country’s contrasting climate zones, are currently unknown. To gain such insights, we estimated land suitability and spatial distribution of lucerne above-ground biomass across New Zealand lands considering contrasting growth conditions (rain-fed or irrigated for different soils types) and two simulation methods of different complexity (process- and GIS-based approaches). This aimed to assess yield-estimate spatial patterns and sensitivity to model selection for a wide range of combinations of water supply (i.e. irrigation and soil water storage) across New Zealand climate zones. For example, highly suitable areas for lucerne cultivation, were estimated in ∼21 thousand km2 when considering the exclusion of steep slopes, poor soil drainage and excess annual rainfall. The two crop-yield models were applied in response to 30 years of daily historical (1971–2000) weather data downscaled at 5 km resolution on suitable areas. Simulated average lucerne yields ranged from ∼4.5–28 t dry matter/ha per year. Simulations showed a distinct spatial pattern of yield decline from north to south, mainly in response to decreasing temperatures. Temporally, water limited yields were up to 4-fold more variable than under irrigation, depending on the degree of drought stress across different years. Results also unveiled systematic spatial patterns of model uncertainty quantified as yield sensitivity to model selection. For instance, simulated yields were most sensitive to model selection (6–31% of total variability, Ti) within high abiotic-stress environments (e.g. low temperature and limited water supply). Overall, soil type selection accounted for most of yield variability (58–78% Ti), being particularly important in warmer environments with variable seasonal rainfall regimes (e.g. northern regions). As expected, water supply (i.e. rain-fed or irrigated systems) was relatively more impactful on yield (8–20% Ti) for limited rainfall areas, where crops are most drought prone (e.g. east coast and central southern regions). Long-term regional scale comparisons of annual lucerne yield, between 30-year simulated distributions and point-based observations from the AgYields database, helped identify hotspots of yield overestimation. Such insights are useful to guide future research on high yield gap areas (e.g. southern colder and drier locations) and highlight key areas for model improvement (e.g. representation of multiple biotic stresses). Overall, our results provide a first gridded-model assessment of lucerne suitability and yield at national scale and quantify the share of variability explained by key climatic, management and methodological components in spatial analysis studies. These insights can inform future modelling efforts and support agricultural planning that considers the expansion of lucerne and other perennial legumes.

Law, justice and the role of courts in changing the social superstructure narrative in climate litigation

Law, justice and the role of courts in changing the social superstructure narrative in climate litigation

How colleges should lead on climate.

How colleges should lead on climate.

Spatial patterns of atmospheric vapour transport and their connection to drought in New Zealand

AbstractThe impacts of drought can be substantial, particularly for primary producing nations such as New Zealand. Despite the importance of drought, identifying connections to atmospheric drivers remains a challenge. Vertically integrated water vapour transport (IVT) is critical to understanding the connection between ocean, atmosphere and the land surface, and as such the drivers of drought events. Self‐organizing maps (SOMs) are used here to characterize the spatial patterns of IVT over New Zealand. In turn, the occurrence of these patterns during drought conditions (defined using the standardized precipitation and evapotranspiration index) across New Zealand is then identified and discussed. The resulting classification highlights a collection of high and low IVT magnitude nodes (i.e., spatial patterns). Low IVT nodes occur 40.57% of the time during all drought events and 45.86% during the top 99th percentile events. Conversely, high IVT magnitude nodes occur less frequently during drought events, at 23.77 and 20.96% of the time during all drought events and the top 99th percentile events, respectively. The low IVT nodes are also particularly dominant during summer and autumn season drought events. An increase in the frequency of occurrence of drought‐associated nodes is observed over the course of the study period, which may in part be associated with El Niño–Southern Oscillation (ENSO)‐driven interannual variability in New Zealand climate. Overall, the results demonstrate the importance of atmospheric circulation‐driven disruptions in moisture transport for drought development, while also providing a first moisture transport weather classification for New Zealand.

The Climate PoLicy ANalysis (C-PLAN) Model, Version 1.0

This paper documents Version 1.0 of the Climate PoLicy ANalysis (C-PLAN) model and presents results for the model's baseline and a policy scenario. The C-PLAN model is a global, recursive dynamic computable general equilibrium (CGE) model tailored to the economic and emissions characteristics of Aotearoa/New Zealand. Distinguishing features in the model include methane-reducing technologies for livestock, bioheat from forestry residues, and explicit representation of output-based allocations of emissions permits. The model was built for the New Zealand Climate Change Commission (CCC) to inform policy advice provided to the government. The computer code for the model and instructions for reproducing results used by the CCC are publicly available. It is hoped that the C-PLAN model will assist transparency in setting climate policies, help build capacity for climate policy analysis, and ultimately set the foundations for future climate policy initiatives in New Zealand and other countries.

Net zero energy buildings in New Zealand: Challenges and potentials reviewed against legislative, climatic, technological, and economic factors

A net zero energy building (NZEB) is a highly energy efficient building that can generate energy through renewable sources that is sufficient to meet its own needs. While NZEBs are being realized in many countries, its emergence in New Zealand remains slow. This study investigates several factors that may cause this issue, namely: legislative, geographical and climatic, technological, and economic factors. The investigation is carried out by secondary data collection and a systematic review of the literature. For the legislative factor, different government statutes, policies, and programs are critically reviewed. For the geographical and climatic factor, the conditions of New Zealand are compared with those of Italy and Japan. For the energy efficiency technological factor, the existing top-rated Green Buildings in the country are analyzed, and the most recurring energy efficient features are discussed. For the renewable energy generation and distribution technological factor, various potential options for on-site and off-site building power sources are discussed, as well as energy storage systems and load matching and grid interaction. For the economic factor, the cost and payoffs of NZEBs are investigated, including the different investment schemes available for potential NZEB developers and how constructing NZEBs can still be feasible post-COVID-19. The study found that New Zealand's climate is suitable for NZEBs and the required technology and economic resources are available. However, more focused and intentional legislations and policies are required to both encourage and incentivize the wider adoption of the NZEB concept in the country.

Trend analysis on frequency of New Zealand climate extremes

Trend analysis on frequency of New Zealand climate extremes

Development of a multi-method chronology spanning the Last Glacial Interval from Orakei maar lake, Auckland, New Zealand

Abstract. Northern New Zealand is an important location for understanding Last Glacial Interval (LGI) palaeoclimate dynamics, since it is influenced by both tropical and polar climate systems which have varied in relative strength and timing. Sediments from the Auckland Volcanic Field maar lakes preserve records of such large-scale climatic influences on regional palaeo-environment changes, as well as past volcanic eruptions. The sediment sequence infilling Orakei maar lake is continuous, laminated, and rapidly deposited, and it provides a high-resolution (sedimentation rate above ∼ 1 m kyr−1) archive from which to investigate the dynamic nature of the northern New Zealand climate system over the LGI. Here we present the chronological framework for the Orakei maar sediment sequence. Our chronology was developed using Bayesian age modelling of combined radiocarbon ages, tephrochronology of known-age rhyolitic tephra marker layers, 40Ar∕39Ar-dated eruption age of a local basaltic volcano, luminescence dating (using post-infrared–infrared stimulated luminescence, or pIR-IRSL), and the timing of the Laschamp palaeomagnetic excursion. We have integrated our absolute chronology with tuning of the relative palaeo-intensity record of the Earth's magnetic field to a global reference curve (PISO-1500). The maar-forming phreatomagmatic eruption of the Orakei maar is now dated to > 132 305 years (95 % confidence range: 131 430 to 133 180 years). Our new chronology facilitates high-resolution palaeo-environmental reconstruction for northern New Zealand spanning the last ca. 130 000 years for the first time as most NZ records that span all or parts of the LGI are fragmentary, low-resolution, and poorly dated. Providing this chronological framework for LGI climate events inferred from the Orakei sequence is of paramount importance in the context of identification of leads and lags in different components of the Southern Hemisphere climate system as well as identification of Northern Hemisphere climate signals.

Commentary on Housing, Health, and Well-Being in Aotearoa/New Zealand.

Housing is poorly constructed for the New Zealand climate and is a major cause of poor health and premature mortality. Private rental housing is older and in poorer condition than public housing and owner-occupied housing. This special issue describes four different approaches to improving housing, which have implications for international housing, health, and well-being policies. The first approach looks at generating the evidence base for improving the quality of the rental sector; the second, the aftereffects of the Christchurch earthquake and the unprecedented role taken by the central government to override local government and community involvement in rebuilding housing and regenerating the city; the third, measuring the effectiveness of the remediation of public housing; and finally, community-based partnerships between community workers and academics to improve the housing of children who have been hospitalized for housing-sensitive hospitalizations.

Trends in national and regional scale drought in New Zealand

Abstract. Drought is a critical natural hazard in New Zealand, affecting both agricultural production and hydro-electric generation. However, the detection and characterisation of drought events are complicated by the range of different drought metrics available. Here, time-series variation in drought is investigated for New Zealand using two commonly used indices: the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). Both the SPI and SPEI are calculated from WATCH Forcing ERA-Interim data (a bias-corrected version of ERA-Interim). Analyses are based on the proportion of New Zealand experiencing at least “moderate” drought (i.e. index values at the threshold of −1 or lower). There is no statistically significant difference in area in drought between the two indices averaged over the time series, and no national-scale trends in drought occurrence are identified. However, a statistically significant trend of divergence between the SPI and SPEI is present when examining drought at moderate spatial coverage (10 % and 20 % coverage based on SPEI), with the SPEI showing increasingly greater drought coverage. These typically become more apparent either as a major drought event is building or terminating. As such, the SPEI generally indicates an extended duration (rather than higher peak extent) of drought events. The spatial expression of the largest SPI-SPEI differences reveals “hotspots” in terms of both average and divergent trends in drought extent, results which are reflected in a regional drought analysis using a cluster analysis of the SPI and SPEI area in drought. In particular, SPEI drought coverage is greater in the South Island east coast and central/southwestern North Island regions. Conversely, SPI drought extent is greater in the eastern North Island. Overall, the differences and similarities in drought extent between the SPI and SPEI can be linked to the highly varied nature of New Zealand climate, with the instances of greater SPEI drought located in regions of driest and most continental climate.

A Community of Practice for Economic Modelling of Climate Change Mitigation in New Zealand

The public and private sectors face important strategic decisions about low-emissions transitional pathways. Such decisions require sound evidence, with input from experts and stakeholders across the board. Models can be used for evidence-based decision-making, but New Zealand has shortcomings in its capacity for climate policy analysis, particularly in comparison with other jurisdictions. These deficiencies pose a serious risk to New Zealand’s future economic development. Climate policy analysis requires assessing a wide range of factors. A multi-model approach supported by multiple providers improves consistency, coordination, and collaboration across members of the modelling community, users of modelling results, and funders of modelling. This document summarises the compelling case for developing a New Zealand ‘Climate Policy Modelling Initiative’ (CPMI). This initiative would coordinate and enhance delivery of modelling across multiple providers. This work is informed by several workshops that brought together economic modellers from a range of organisations. If supported by government leadership and commitment, the CPMI would have a transformational effect on New Zealand’s capacity to plan for a successful low-emissions future.

The presence of moisture deficits in Miocene New Zealand

Abstract New Zealand climate during the early to middle Miocene was subtropical to warm-temperate, in contrast to the predominance of cool-temperate climates in New Zealand today. Both modern and Miocene environmental settings of New Zealand are strongly moderated by the surrounding ocean. Seasonal moisture deficits occur today in rain shadow regions in New Zealand, but the potential and nature of seasonal moisture deficits under globally warmer conditions is uncertain. Here, we reconstruct seasonal moisture balance (precipitation – potential evapotranspiration) using seasonal temperature and mean annual precipitation estimates derived from early to middle Miocene (23–11 Ma) fossil leaf assemblages, combined with a Penman-Monteith model for potential evapotranspiration. The model incorporates uncertainty in temperature, precipitation, vapor pressure deficit, radiation and wind speed. Our results suggest that three out of nine sites investigated have a very high potential for summer moisture deficits (lowest monthly moisture balance

Eco-friendly and low-cost Enhanced Pond and Wetland (EPW) system for the treatment of secondary wastewater effluent

To demonstrate the feasibility of Enhanced Pond and Wetland (EPW) system for the treatment of Biological Trickling Filter (BTF) effluent, pilot-scale EPW systems were installed and operated in New Zealand climate conditions. The system consisted of: two High Rate Algal Ponds (HRAPs) followed by gravity Algal Harvesters (AHs), two Surface Flow Constructed Wetlands (SFCWs), and a Woodchip Denitrification Filter (WDF). The wastewater treatment performance of each treatment component was monitored fortnightly over six months (late autumn to winter) in terms of TSS, total and soluble BOD5, nutrients (N and P) and E.coli removal. Algal biomass production, algal harvest efficiency, and algal dominance in the HRAPs were also determined. The pilot-scale system maintained low final effluent TSS and BOD5 concentrations below 5 and 8 mg L−1 respectively, and achieved high removal of nitrogen (NH4-N: ∼95%; NO3-N: 77%), phosphorus (DRP: ∼65%) and E. coli (at least 3-log E. coli removal) throughout the experimental period. Particularly in autumn, the HRAPs achieved almost complete removal of both NH4-N (5.0 to <0.3 mg L−1) and NO3-N (3.4 to <0.2 mg L−1) mainly through algal assimilation. Furthermore, when sunlight U.V radiation was high, ∼4-log E. coli removal (104 to <2 cfu/100 ml) was achieved in the HRAPs mainly through sunlight disinfection. The HRAPs had algal biomass productivity of 7.2 and 4.1 g m−2 d−1 in autumn and winter respectively, and the algal biomass was efficiently removed in AHs by gravity sedimentation (∼80% TSS removal after 6.5 h settling) through bio-flocculation under nitrogen limiting conditions (<0.5 mg L−1). Overall, the Enhanced Pond and Wetland system can efficiently treat secondary wastewater effluent from a domestic wastewater treatment plant and produce a high quality final effluent with minimum energy inputs.

Communicating for Systemic Change

&#x0D; The climate crisis significantly magnifies the urgency of implementing systemic change. Globally, we have little time remaining in which to bring about the social, political, and economic transformation needed to avoid triggering amplifying feedbacks and runaway climate chaos. In this context, a core challenge is how to mobilise people and inspire widespread action to create this transformation. Understanding current approaches to climate communication is crucial for ensuring that our communication practices play the vital role they will need to in the coming decades. In this article, I do not aim to provide a comprehensive set of guidelines that define effective climate communication. My primary aim is to understand current communication practices. To achieve this, I take a movement-centred activist-scholarship approach to research on climate communication decision-making via in-depth semi-structured interviews with 14 members of the New Zealand climate movement. My intent is to synthesise the perspectives and experiences of New Zealand climate movement participants. Through this, I hope to offer a useful analysis of significant dynamics in climate communication and shed light on dynamics in systemic change communication more broadly.&#x0D;

Adaptation Issues in New Zealand's Climate Change Policy

New Zealand is already experiencing the effects of a warming climate and needs to adapt its built, social and ecological systems to reduce vulnerability to climate impacts. Currently, there is no coordinated approach to climate change adaptation in New Zealand. There is no overarching policy or legislation provided by central government to guide adaptation action by other sectors. Amongst other issues, it is unclear how climate change adaptation will be funded. This paper evaluates some of the challenges present in New Zealand’s current adaptation framework. It argues that adaptation requires policy response from central government. Mitigation of carbon emissions can no longer be the sole focus of climate change policy. This paper proposes that climate change adaptation be addressed in legislation by requiring central government to engage with the issue through a series of policy documents. These would include a national climate change risk assessment, a national adaptation plan, and an independent adaptation progress report. These documents will be updated every five years and will thus provide for a coordinated response to adaptation that allows progress to be monitored and evaluated.