Climate and health

Objectives To review and thematically map published research on health-related climate change mitigation or adaptation interventions in Australia. Study Design Systematic mapping of published peer-reviewed research studies and reviews examining outcomes associated with climate change and health interventions in Australia. Data Sources MEDLINE, Scopus, Google Scholar, published from 1 January 2008 to 1 March 2024, and manual searches of peer-reviewed literature. Data Synthesis Eighty-three publications (49 original research, 34 reviews) were included, categorised under four themes: (i) health system decarbonisation (18); (ii) health system adaptation, vulnerability and resilience (24); (iii) health co-benefits of climate change mitigation (9); and (iv) adaptation outside the health system to protect health from climate impacts (26). Six additional studies spanned several of these themes. Ten decarbonisation studies focused on hospital-based clinical care interventions. In comparison, adaptation studies focused on interventions in a wider variety of health services and community settings. Twenty publications focused on heat, with fewer publications on other climate-related hazards (bushfires, floods and droughts). Adaptation interventions largely focused on addressing physical health impacts of climate change, with less attention on psychosocial or mental health impacts. Studies on health co-benefits of mitigation focused on urban greening, shading, cool materials, healthier diets, carbon pricing of food and Indigenous land management. Across all themes, four studies focused on First Nations peoples. Original studies mainly used survey methods, with three studies employing randomised controlled trials and seven using life cycle assessments. Overall, there was limited evidence of stakeholder engagement. Conclusions A sustained increase in research on climate change and health interventions will help realise the vision of ‘healthy, climate-resilient communities, and a sustainable, resilient, high quality, net zero health system’ of the National Health and Climate Strategy. Evidence from local contexts and priority populations, using interdisciplinary methods and stakeholder engagement, will support action on climate change and health in Australia.

Sotiris Vardoulakis, Luise Kazda, Rebecca Haddock, Alexandra L. Barratt, Forbes McGain, Kinley Wangdi, Enembe Okokon, Daniela Espinoza Oyarce, Gopika Indu, Nigel Goodman, Veronica Matthews, Phoebe Spurrier, Alice McGushin, Georgia Behrens, Madeleine Skell

In December 2023, the Australian Government released its first National Health and Climate Strategy.1 Acknowledging that the health effects of a changing climate are already being felt across the country, this strategy set out a whole‐of‐government plan for addressing the health and wellbeing impacts of climate change. A core component of this strategy is health system resilience — that is, building capacity to anticipate, understand, plan for, and respond to escalating climate impacts on health, wellbeing, and the delivery of care. What does it mean in practice to build health system resilience to climate change? In this issue of the MJA, Stewart and colleagues2 present findings from a randomised controlled trial that provides an instructive example. Their research was premised on the recognition that seasonal and acute weather conditions are drivers of cardiovascular events. Climate change is expected to generate more weather extremes that will, in turn, provoke more cardiovascular events. They hypothesised that a tailored, multifaceted intervention designed to build resilience to external provocations to health would increase days alive and out of hospital among people with multimorbid heart disease, compared with standard care. Their intervention aimed to address the bio‐behavioural vulnerability to environmental challenges to cardiovascular health, including participant behaviours, home environmental conditions, clinical factors, and socio‐economic resources. The study did not find statistically significant overall differences between the intervention and standard care groups for the primary outcome (days alive and out‐of‐hospital) and all‐cause hospital readmission and death. However, hospital readmissions were more frequent after dynamic weather events, including storms and acute temperature changes. After adjusting for timing of follow‐up, the intervention was associated with significantly fewer days of hospital stay during the summer months. These findings, the authors contend, “challenge the assumption that the management of people with chronic heart disease should be the same all year round” and provide a compelling basis for future research. Writing in the editorial linked to this research,3 Hunter explains that “despite its negative findings, this trial illustrates a critical inflection point in how we conceptualise health and disease in the context of an increasingly volatile climate” and that “the biopsychosocial model must evolve to more explicitly acknowledge the foundational relationship between human health and the environment”. The National Health and Climate Strategy represents a positive move in this direction, as does the incorporation of climate change, environmentally sustainable health practice, and planetary health into medical school curricula,4 and the development of climate change and health adaptation plans by Australian states and territories.5,6,7 Yet there is still clearly a long way to go, with recent Australian research8 indicating that despite health system adaptations to extreme weather events resulting in workforce capability, costs, demand, and health outcome benefits, important gaps remain in areas such as financing and access to medicines, and, crucially, “how these elements come together to build health system resilience is unclear”. At the MJA, we look forward to the opportunity to publish future work that advances our understanding of this important area.

Elizabeth Zuccala

As I am writing this Editor's Choice, I am in the process of preparing our house in Queensland for a cyclone, predicted to hit Brisbane in about 48 hours. The cover topic of this month's issue of the MJA is therefore very much at the front of my mind. This issue contains the seventh report of the MJA–Lancet Countdown on health and climate change, which examines five broad domains: health hazards, exposures and impacts; adaptation, planning and resilience for health; mitigation actions and health co‐benefits; economics and finance; and public and political engagement (https://doi.org/10.5694/mja2.52616). The analyses by Beggs and colleagues have some unsurprising but still concerning findings: the exposure to heatwaves in Australia is growing, which in turn increases the risk of heat stress; other health threats such as bushfires and drought — “features of the continent for millennia” — are amplified by climate change. Cyclones, as we are currently facing, are noted as major causes of economic losses. This year, the authors also report against a new indicator: climate litigation over the past decade. The findings are instructive: one case is “a legally significant acceptance, by government, of the science concerning the health impacts of climate change”. However, litigation is just one driver of change. As the authors note: “Nationally, regionally and globally, the next five years are pivotal in reducing greenhouse gas emissions and transitioning energy production to renewables. Australia is now making progress in this direction. This progress must continue and accelerate, and the remaining deficiencies in Australia's response to the health and climate change threat must be addressed”. Another perspective in this issue of the MJA discusses the importance of Australia endorsing a fossil fuel non‐proliferation treaty (https://doi.org/10.5694/mja2.52610). Colagiuri and colleagues outline the aims of the Fossil Fuel Non‐Proliferation Treaty and why it is relevant to health. Starkly put, we are not on track to meet the goals of the Paris Agreement — and as events in the United States unfold, it seems as if political will is shifting even further away from support for the agreement. The authors argue that the Fossil Fuel Non‐Proliferation Treaty is a way to directly address the key driver of the climate crisis. It has not been signed by Australia, perhaps unsurprisingly, though eleven Pacific nations, which well understand the risk, have signed on. Endorsing the Fossil Fuel Non‐Proliferation Treaty would, the authors argue, be “more than just a climate strategy for Australia; it represents a vital step towards advancing global health justice and fostering regional solidarity”. How pharmaceutical companies are progressing in their carbon emission plans is assessed in a research article by Burch and colleagues (https://doi.org/10.5694/mja2.52621). Drawing on publicly available documents on actions during 2015–2023 for the ten largest pharmaceutical companies operating in Australia, they show a very mixed set of results. Some have Science Based Targets initiative (SBTi)‐approved targets, monitoring, commitments and evidence of action; others have commitments to SBTi‐approved targets but limited publicly disclosed records; and others are without public commitments to achieving net zero emissions, and minimal or no SBTi‐approved targets. As the authors conclude, the companies are moving at different rates. Though this is just a snapshot, such monitoring and public documentation are vital for policy makers in supporting change. The final article I will highlight touches on a topic — snake bite and its sequelae — that may become more relevant as the climate warms and humans are more exposed to snakes (https://doi.org/10.5694/mja2.52622). In a study spanning 15 years, Isbister and colleagues analyse data from people bitten by snakes, whether they had an early collapse, and the features associated with the collapse. Not surprisingly, they found that early collapse is associated with poorer outcomes. Data on these patients are not easy to collect, but the conclusion that early collapse requires prompt identification and cardiopulmonary resuscitation is a useful clinical finding. Increasingly, the association between a changing climate and the effects on human health are becoming clearer and more urgent. If there is one overarching lesson from all these articles, it is that as every year passes, the importance of action becomes even necessary, and the time frame for action is shortening.

Virginia Barbour

The extraction and burning of oil, coal and gas is overheating our planet. The result is a changing climate that is becoming more extreme and less predictable. According to the Bureau of Meteorology (https://media.bom.gov.au/releases/1250/preliminary‐summary‐of‐australias‐climate‐in‐2024), for instance, 2024 was Australia's second hottest year on record. With intensifying climate events like extreme heat, drought, flooding and bushfires, as well as associated threats to biodiversity and food and water security, come myriad adverse impacts on health. Two articles in this issue of the MJA speak to the health implications of the climate crisis and the policy responses required to rise to this challenge. Until recently, local transmission of Japanese encephalitis virus (JEV) in Australia was limited to the Torres Strait and Cape York. A widespread outbreak in 2022–23 in New South Wales, Queensland, Victoria and South Australia heralded that the country might be entering a new era in the epidemiology of this mosquito‐borne virus. Indeed, at the end of last year, Victoria reported its first case of JEV since the last outbreak (https://www.theguardian.com/australia‐news/2024/dec/31/japanese‐encephalitis‐case‐found‐in‐victoria‐prompts‐high‐risk‐warning). Dowsett and colleagues (https://doi.org/10.5694/mja2.52550) explain how a changing climate could be contributing to the emergence and spread of JEV in Australia through increases in rainfall, temperature and levels of evaporation and humidity, which in turn affect the interactions between JEV vectors, hosts and the environment. After reviewing Australia's JEV surveillance efforts to‐date, Dowsett and colleagues conclude that “there is a pressing need to shift from a reactive ‘surveillance and response’ approach to a more proactive, comprehensive ‘predict and prevent’ strategy, particularly in regional areas of Australia where populations are at greater risk”. Key recommendations for action include developing comprehensive surveillance systems that target multiple diseases with overlapping ecology and transmission (such as JEV, West Nile virus, and Murray Valley encephalitis virus), utilising multidisciplinary One Health approaches, and the creation of a central data repository to assist in the rapid detection and containment of outbreaks, potentially led by the nascent Australian Centre for Disease Control (www.cdc.gov.au). These efforts should be complemented by enhancing research capacity for the diversity of vector‐borne diseases that affect Australia and our region. Recognising that our population is already experiencing the impacts of climate change on health and wellbeing, in December 2023, Australia launched its first National Health and Climate Strategy (https://www.health.gov.au/our‐work/national‐health‐and‐climate‐strategy). Writing in the MJA, Beherns and their colleagues (https://doi.org/10.5694/mja2.52552) from the Australian Department of Health and Aged Care outline the core aims and elements of this landmark strategy, reflect on its first year, and discuss anticipated implementation challenges. The authors explain that “at the heart of the Strategy is an ambitious agenda to transform Australia's health system into one that is sustainable and climate resilient while improving care quality and health outcomes”. Since its launch, work has begun on 31 of the 49 actions within the Strategy, with 12 of those 31 actions completed or in the final stages of completion by the end of 2024. Planning has also commenced for a further 14 actions. One particularly important element of the Strategy is the ongoing development of a Health National Adaptation Plan (HNAP). These national plans are an initiative under the United Nations Framework Convention on Climate Change, and are intended to provide a national framework for countries to anticipate and manage climate‐related health risks. According to the latest global report from the Lancet Countdown on health and climate change (https://www.thelancet.com/journals/lancet/article/PIIS0140‐6736(24)01822‐1/abstract), as of December 2023, 43 of 82 (52%) countries that had committed to building climate‐resilient health systems through the COP26 Health Programme reported having developed an HNAP, up from just 6% the year before. Australia's commitment to developing its own national plan thus represents a significant step towards building climate resilience within our health system and bringing the country in line with global best practice on climate and health action. Overall, the success of Australia's National Health and Climate Strategy must be assessed in the long term and will undoubtedly face setbacks and resistance. It must also be judged in light of actions taking place in other areas of government, not least of which include the ongoing new approvals of fossil fuel projects and enormous financial subsidies to major producers and users of fossil fuels — actions that are incompatible with efforts to avoid the worst effects of climate change. Nonetheless, early progress on implementation of the Strategy is encouraging, especially given the arguably catastrophic national inaction on climate change and health that characterised the years preceding its announcement. Owing to its importance for Australia, planetary health is a core focus of the Journal and we encourage our authors to continue to submit research and analysis in this area.

Elizabeth Zuccala

This issue of the MJA returns to the topic of climate and health, with the publication of the 2023 report of the MJA–Lancet Countdown on health and climate change, focusing on the need for sustainability in Australia's health care sector (doi: 10.5694/mja2.52245). This is the sixth report in this series. The Countdown on health and climate change in Australia was established in 2017, producing its first national assessment in 2018. The report comes after yet another catastrophic year for the climate with 2023 having been the hottest year on record (https://www.climate.gov/news‐features/understanding‐climate/climate‐change‐global‐temperature) and following extreme floods in Australia in 2022. The early reports appeared in the context of the severe 2017–2019 droughts; this year's report “thus [completes] a picture of Australia's drought‐to‐flood cycle”. As in previous years, the report tracks progress on five broad domains: health hazards, exposures and impacts; adaptation, planning and resilience for health; mitigation actions and health co‐benefits; economics and finance; and public and political engagement. In the run‐up to 2030, the next phase of the countdown is even more critical. Although they observe signs of progress, including the release of Australia's first National Health and Climate Strategy, the authors note that their “results highlight the health and economic costs of inaction on health and climate change”. The MJA will continue to publish on health and climate change, and we encourage submissions in this area. Elsewhere in the issue, Pemberton and colleagues highlight the growing challenge of care of older people within the prison population, especially at the end of life (doi: 10.5694/mja2.52240). Reports regularly emerge of patients being subject to restraints, even when very frail and in palliative care, despite doctors calling for restraints to be removed. As the authors conclude, it seems clear that when prisoners enter hospital or palliative care, the justice and health care systems are directly challenging each other. The authors note that this is an important reminder that international standards require “prisoners should be entitled to the same level of health care as the wider community”. Finally, an editorial and research article explore how Aboriginal and Torres Strait Islander caregivers are involved in parenting programs. In their scoping review of randomised controlled trials (RCTs) (doi: 10.5694/mja2.52198), MacDonald and colleagues assess the extent to which Aboriginal and Torres Strait Islander parents, particularly fathers, are included in trials of parenting programs in Australia and whether these programs are culturally appropriate. The answer is unfortunately that Aboriginal and Torres Strait Islander families have been engaged in such studies to only a very limited degree. The authors' conclusions are sobering: “We could not identify any RCTs in which the participation of Aboriginal and Torres Strait Islander fathers was reported, and few interventions were tailored to the cultural needs of Indigenous people.” In their editorial, Sherriff and Gwynn reinforce this concern (doi: 10.5694/mja2.52238), although they note that “RCTs are generally not the preferred method of assessment for Aboriginal communities because direct benefits are not evident and they do not conform with cultural views on reciprocity and community‐centred approaches”. As they conclude, “Aboriginal ways of knowing, being, and doing must be privileged across all aspects of research in their communities”.

Virginia Barbour