THE climate crisis is also inextricably a health crisis. To prepare health care systems for the future, climate change must be seen as a priority issue.

The voices and knowledge of health professionals and health consumers need to be incorporated into every country’s response. A broader view is crucial to understand not only the social determinants of health but also the cultural determinants of health, wherein the contribution of local knowledge is incorporated into the response to climate change.

Climate change affects human health, which drives health care use

As the Earth warms, we are experiencing more frequent and severe heatwaves, fires, floods, droughts, and other extreme weather events. The likelihood of new infectious and vector-borne diseases is also increasing. These risks pose both immediate and long term negative effects on physical and mental health, increasing the pressure on health care services.

When bushfires ravaged New South Wales, for example, demand for emergency department care in respiratory illness in the Riverina area increased by 86% in the second week of January 2020; the longer term impacts of these bushfires on human health will not be known for some time.

Moreover, the impacts of climate change on health are unevenly distributed in our society. Indigenous communities, people living with chronic health conditions, the frail aged, people with socio-economic disadvantage, and people from culturally and linguistically diverse backgrounds are all more vulnerable to the consequences of climate change.

Signatories to the Paris Agreement in 2016, including Australia, acknowledged their citizens’ rights to health in the context of climate change. However, before the COP26 Conference in Glasgow, it was clear that most had failed to recognise the health co-benefits of addressing climate change and the importance of measuring how climate change policies affect human health.

Health care systems also contribute to climate change

On average, health care accounts for up to 5% of the world’s carbon footprint, with hospitals and pharmaceutical companies being the major contributors. Every step of the health care process, from powering buildings to the essential activities involved in providing care to patients, generates substantial amounts of greenhouse gases. On the current trajectory, it is estimated that health care’s carbon footprint could triple by 2050. Furthermore, the pandemic exacerbated the impact of plastic and single-use medical items, such as personal protective equipment, on the environment.

Wasteful practices in health care also contribute. Up to 30% of health care activities provide marginal or no health gain. This includes activities such as low value surgery, duplication of tests, and inappropriate medication prescribing (eg, antibiotics for viral infections). Reducing these practices could save over 8000 kilotons of carbon dioxide (CO2) equivalent emissions per year in Australia alone.

Building resilient health care systems

As populations age and the prevalence of chronic ill-health increases, the financial and environmental costs of providing care risks becoming insurmountable. Addressing these problems necessitates a whole-of-system approach, with sustainable change made at every level from governmental and local policies to stakeholder behaviour.

Some funding bodies, such as the European Commission on Health Research and Innovation and the National Health and Medical Research Council (NHMRC), have initiated mechanisms to address health care systems’ resilience and preparedness to respond to climate change. But so far, not enough priority has been given to health services evaluation and implementation funding, without which these programs may not result in sustainable change to the system.

An integrated system, including digital monitoring of acute and primary care health service usage, could deliver better results. A learning health care system such as this would synthesise information from every patient encounter and from medical research, improving the continuity of care and enabling better planning to reduce wasteful practices.

Reining in the health care systems’ carbon footprint

At COP26, health was a priority for the first time. The new COP26 Health Programme initiative called on countries to commit to creating a low carbon health care system, assessing baseline levels of greenhouse gas emissions, including supply chains, and for high and middle-income countries to achieve zero net emissions by 2050 or before. Fifty countries have now committed to transforming their health care systems.

Several countries, such as the UK, have already made progress on this commitment. Part of the UK’s National Health Service pledge to decarbonise their health system emphasises improving patient care while lowering environmental and social costs. Adopting more stringent environmental policies is likely to have economic benefits as well.

Every Australian state and territory health department has produced a review on improving the resilience and sustainability of their health care systems. These discuss reducing the environmental effects of health care from energy use to reducing water usage, food waste, and the impact of medical devices.

However, programs and policies are also needed to help reduce wasteful care. This includes education for health providers and health consumers as well as funding mechanisms to promote high value care (that is, care that improves patient outcomes). A learning health care system with digital monitoring as its centrepiece could improve adherence to health care guidelines, reduce unnecessary pathology testing (including duplication or testing inappropriately) and facilitate knowledge sharing, optimising efficiency.


The pledges at the COP26 Conference to limit CO2 and methane emissions provide some hope that global temperature increase can be kept below 2⁰C, but only if these pledges are met and sustained for decades to come. Health care systems must adapt to the climate crisis happening right now and prepare for future consequences of climate change.

On 2 December, the NHMRC Partnership Centre for Health System Sustainability will host a webinar with key experts, examining the challenges facing health systems caused by climate change. Visit our website for more information and to register.

Professor Jeffrey Braithwaite is the Founding Director of the Australian Institute of Health Innovation (AIHI), Macquarie University, and leads the NHMRC Partnership Centre for Health System Sustainability (PCHSS).

Associate Professor Yvonne Zurynski is Associate Professor for Health System Sustainability at AIHI and the co-lead for the Observatory on Health System Sustainability within the PCHSS.

Dr Carolynn Smith is a Research Fellow with the PCHSS and the NSW Roots and Shoots Coordinator for the Jane Goodall Institute Australia.

Professor Lesley Hughes is a Distinguished Professor of Biology and Pro Vice-Chancellor (Research Integrity and Development) at Macquarie University. She is a former lead Author on the IPCC’s 4th and 5th Assessments and a former federal Climate Commissioner. She is a founding Councillor with the Climate Council of Australia.




The statements or opinions expressed in this article reflect the views of the authors and do not represent the official policy of the AMA, the MJA or InSight+ unless so stated.

One thought on “Climate change, human health, and health care systems

  1. Anonymous says:

    There is another area of health care that can have a HUGE impact on climate change and that is contraception.
    If every child on the planet is a planned one, the size of the human carbon footprint will be much reduced!
    Every doctor can be encouraging their patients of reproductive age to have reliable contraception, and remain aware of the poor evidence base for “the app on my phone” to control fertility. It is time for the Australian Government to consider free contraception (as is the case in the UK and South Africa and many other countries.)

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