Ensuring the resilience of health systems in the face of the effects of climate change
Abstract
The health of the planet and that of people are inextricably linked. As the environment deteriorates, human health is directly and indirectly impacted by the increased prevalence and severity of existing and emerging diseases.
More specifically, climate change is one of the major challenges we have to address in order to safeguard future health as well as to ensure continuity of care and the effectiveness of health systems.
Health systems suffer direct impacts from climate change and face four distinct challenges.
1. Becoming resilient: heath infrastructures are impacted by the effects of climate change, such as the need to cool premises during heatwaves, disruptions to energy supplies, and securing logistics chains.
2. Preparing for the exacerbation of chronic diseases that will lead to an overload of the health system.
3. Identifying faster and more effective treatments for patients affected by the effects of climate change.
4. Finding a way to embed prevention into patient pathways.
Equally, health systems must cut their environmental impacts, particularly their greenhouse gas emissions: they are responsible for around 5% of total global emissions, equivalent to the world’s fifth largest emitting country.
It makes for a complex equation. All stakeholder groups, each with a specific role to play, must be involved in designing and adopting solutions while also accelerating the implementation of “carbon neutral” health systems that are equitable and prioritize patient well-being.
Outline
Top of pageFull text
Introduction
1The environment is being increasingly impacted by anthropic activities, triggering significant disruptions to a long-established equilibrium between the health of the planet and the health of populations. The changes this has led to can be summarized as a threefold planetary crisis: pollution, climate change, and loss of biodiversity.
2These changes are already resulting in an increase in the number of patients and deaths, a trend likely to continue. For example, they lead to propagation of vector-borne diseases in new parts of the world, deterioration of health conditions as a result of severe climate events, and the emergence of new threats linked to human activities such as urbanization or intensive agriculture.
3Just like the people they serve, health systems are vulnerable to climate change. But they are also responsible for 5% of global CO2 emissions. This means that as well as becoming more resilient in the face of the effects of climate change, they also need to innovate in terms of care pathways to address the rising number of patients.
4To combat the global threat that climate change poses to the planet, human health, and health systems, we need to think of them in terms of one integrated system.
Climate change: a challenge facing health systems
5Climate change poses one of the greatest threats to human health. Its effects on people, exacerbated by climate injustice, are spreading across the world at an increasing rate and entering a spiral seemingly beyond control, leading to an increase in the number of patients and deaths, displaced and vulnerable people.
6Just like the people they serve, health systems too are vulnerable to climate change and subject to a wide range of new pressures, including:
-
their own vulnerability to extreme weather events that may impact infrastructure, including logistics chains, lead to power outages and a decrease in labor productivity;
-
increased hospital admissions and deaths caused by rising temperatures;
-
the evolving patterns of water-borne and vector-borne diseases which threaten to unravel decades of progress in the control of infectious diseases;
-
the growing prevalence of infectious diseases and their spread into new regions;
-
the exacerbation of chronic diseases caused by climate change (asthma, chronic obstructive pulmonary diseases, hypertension, diabetes, and mental illnesses) which increase the pressure on healthcare facilities and the use of medical care.
- 2 World Economic Forum (2024). Quantifying the impact of climate change on human health. World Econom (...)
7By 2050, climate change is likely to cause 14.5 million deaths and 12.5 trillion dollars in economic losses worldwide.2 Climate-induced impacts will account for a further 1.1 trillion dollars in extra costs to healthcare systems, creating a significant additional burden on already strained infrastructures and medical and human resources.
- 3 M. Romanello, A. McGushin, C. Di Napoli C et al., Lancet 398(10311): 1619-62, The 2021 Report of Th (...)
8At the same time, health systems are responsible for almost 5% of global CO2 emissions: 50% relates to supply chains and product manufacture; 45% to patient care pathways, and 5% to research and development, including clinical trials.3
9Health systems thus have to tackle multiple challenges that require them to anticipate and adapt, improve scientific knowledge and predictive models (climate-health correlations), and invest in health-related interventions (prevention, diagnostics, products, etc.) that are better aligned with the risks. Sharing information on a large scale is also a priority so that all actors concerned can be alerted by public health campaigns.
10There are reciprocal links between the climate and health/health systems. This means that actors from the health sector must play an active role in accelerating their resilience in the face of climate-related effects, and by altering care pathways in efforts to decarbonize. At the same time, they have to plan ahead to deal with the health crisis facing the world.
Improving the resilience of health systems
11Health systems are vulnerable to climate change: extreme weather events such as floodings, fires and heatwaves can have an impact on infrastructure, personnel and supplies at a time when a larger number of patients will be streaming into health facilities.
12This situation has already occurred in several parts of the world, highlighting the need to bolster the resilience of health systems, including the ability not only to tackle climate events but also to recover after them while continuing to guarantee continuity of care.
- 4 Earthzine (June 28, 2011). Code Grey: Protecting Hospitals from Severe Weather. https://earthzine.o (...)
- 5 Seltenrich, N. (2018). Safe from the storm: Creating climate-resilient healthcare facilities. Envir (...)
13In the USA, the Federal Emergency Mana-gement Agency estimates that a single extreme weather event could cost a hospital between 600,000 and 2 billion dollars4 in damage to equipment and infrastructure and create on-going disruption due to repairs at a time when every effort is being made to keep the hospital running. As an illustration, in 2012 hurricane Sandy led to the evacuation of more than 6,400 patients from six hospitals and 31 residential care facilities. NYU Langone Medical Center, one of the hardest hit hospitals, suffered nearly a billion dollars in damage,5 remaining fully closed for two months and without an emergency room for a year and a half.
14It is important to focus on anticipation, and the accessibility and effectiveness of care. This includes adaptation planning, infrastructure resilience, improving capacities for access and delivering care, and preparing emergency rooms so they are ready for climate events.
15Mechanisms to monitor, predict and respond to diseases as well as innovative solutions for healthcare and drug delivery must also be put in place.
16As an example, respecting the cold chain when storing and distributing certain vaccines can be a challenge in some countries: access to the energy needed to maintain the temperature that ensures the quality and safety of products can be a real struggle when outdoor temperatures keep soaring.
- 6 Nair P. (August 29, 2018). Kerala floods: Health directorate estimates Rs110 crore loss. Kochi News (...)
17In India, flooding in the state of Kerala in 2018 had a major impact on the state’s public health system. In many countries the back-up electricity supply is designed to last for 72 hours. In Kerala, hospitals had to deal with power outages lasting from three to nine days, which caused refrigerated storage systems to shut down unexpectedly. Many hospitals reported that their entire stocks of vaccines and other essential medical supplies requiring refrigeration had been damaged, as has IT hardware, leading to the loss of patient records at several hospitals. The public health administration estimated that public hospitals sustained losses of over 15 million dollars.6
18To put all this in place requires authorities and health stakeholders to be aware of the issues and have access to financial and human resources that can appear outsized relative to their capacities. But what will happen if nothing is done? Health stakeholders have to make substantial investments today to respond to current and future impacts on their health systems and avoid the cost of inaction further down the line. This also requires changes in government policies.
Innovating to change care pathways
- 7 French Ministry of Health and Solidarity (2023). Presentation of the PESS program: priority on Prev (...)
19Care pathways account for 45% of CO2 emissions of health systems in France (estimated at 50 million metric tons of CO2 equivalent, or over 8% of all French emissions).7 Transforming the way care is delivered to anticipate and cover the growing demands of patients impacted by climate change is a major challenge. Meeting it may have revolutionary effects on health policies and people’s behaviors.
- 8 Real-world data is information that is not collected as part of an experiment but when patients rec (...)
20This transformation must also be paired with collection on a massive scale of real-world data8 on the links between climate change and health. It will improve understanding of these links, raise awareness of the scale of the looming crisis, and help finding rapid and effective solutions.
Seven levers for reducing emissions in care pathways
21There are possibilities for decarbonization at every stage of the care pathway, which can be summarized as seven priority levers that also contribute to delivering quality care. These levers can be grouped into three main themes:
-
decarbonizing health facilities and vehicle fleets (renewable energies and electric ambulances) and adopting circularity principles in health treatments (such as using reusable and recyclable materials);
-
improving disease prevention and management to reduce their frequency and severity and increasing the efficiency of treatments;
-
delivering care differently, by improving the overall efficiency of healthcare provision and selecting interventions with a lower carbon footprint, while simultaneously delivering similar or improved outcomes in terms of patient care.
22We describe below how prevention and innovation via digitalization are levers for improving care pathways.
Improving prevention and care: preventing the appearance of diseases
23Reducing risk factors and preventing the appearance of diseases are the most effective strategies for reducing the disease burden facing our societies, particularly in relation to non-communicable diseases. At the same time, these actions also help to shrink the carbon footprint of healthcare.
24Addressing the causes, such as air pollution, is a necessity. Rolling out effective measures on a massive scale (such as healthy and sustainable environments in towns and cities, regular physical exercise, and a varied diet) requires unstinting backing from public bodies and considerable resources if we want to see rapid improvements.
- 9 Hudson R et al. (December 2023). Assessing the Carbon Intensity Profile of an Immunization Program (...)
25In terms of prevention, vaccination programs are effective in safeguarding health. As well as cutting patient numbers, hospitalizations and even deaths, vaccination can also be a potential source of cuts in CO2 emissions. A study run by Sanofi9 in the United Kingdom illustrates this potential, highlighting health-environment prevention co-benefits in the choice of an early vaccination scenario for all infants at birth against bronchiolitis, compared to other immunization programs. By simplifying care pathways and reducing hospitalizations and primary care visits, the “all newborns” vaccination scenario could deliver a 68% fall in CO2 emissions compared to the current situation.
- 10 Intergovernmental Panel on Climate Change. (2023, March 20). Sixth assessment report: Synthesis rep (...)
26Health prevention efforts targeting the most vulnerable, victims of the effects of climate change and inhabitants of the areas most impacted is also central, bearing in mind that approximately 3.6 billion people in the world live in areas exposed to climate risks.10
Delivering care differently
- 11 For more information, visit the DCarbon website, Sanofi’s partner for the study - https://dcarboneg (...)
27Delivering care remotely as well as locally, where appropriate, offers alternatives to be explored in greater depth. Using solutions such as telemedicine and wearable devices can reduce the need for patient travel and increase access to specialist care, reducing CO2 emissions without compromising quality of care. A study launched in Egypt11 into a patient cohort suffering from asthma and atopic dermatitis has shown that telemedicine delivers a fall of almost 74% in CO2 emissions relating to their care (when taking into account the impact of digital technology on the environment). Furthermore, patient well-being is enhanced by not having to travel and risk exposure to air pollution or stigmatization due to the appearance of their skin.
28Remote monitoring for non-communicable diseases has also been shown to improve health outcomes.
29However, attention must be paid to the impact on accessibility for different population groups.
30Local treatment provision also helps reduce CO2 emissions. The role of pharmacists, community nurses, and local healthcare structures is crucial to decarbonization, a reality that calls for changes in national and community health policies.
Eco-design for health products
31Today’s health systems pay close attention to the climate footprint of health products and increasingly require manufacturers to provide products with positive environmental performances as a lever for improving the carbon footprint of patient pathways. This requires the establishment of recognized assessment methods approved by committees repre-senting various stakeholders. Work under way at present is targeting the publication of an international standard in 2025. This major advancement, initially intended for health industry professionals to help them embed eco-design as far upstream as possible, is now widely supported by buyers, health authorities, insurance providers, etc.
32It is nevertheless important to avoid focusing on the wrong targets:
-
a product’s climate footprint is not enough in itself to characterize the impact a product has on the environment;
-
equally, it is a mistake to assess the climate footprint of a care pathway simply by looking at the climate footprint of a product. The product's contribution to improving the environmental footprint of the overall car pathway must be examined, along with the activation of other intervention levers;
-
improvements in patient health remain the overarching priority when determining a health treatment.
The need for data collection
33Although there is ever-growing acknowledgement of the links between climate and health, gaps remain in the production, collection and sharing of data on mechanisms that trigger or exacerbate climate change-related diseases.
- 12 Sanofi (June12, 2024). The Link Between Climate and Health: We Chart a New Course https://www.sanof (...)
34Sanofi has recently undertaken a study12 that seeks to identify links between disease areas and the impacts of environmental change. The study concentrates on treatment and prevention in five therapeutic fields: immunology, infectious and vector-borne diseases, pandemic pathogens, chronic non-communicable diseases (such as cardiovascular diseases and cancer), and allergies.
35This study examined 6,843 published reports and highlighted the fact that, of all the environmental risks identified, air pollution has the greatest negative impact on the disease areas concerned. It also showed that cardiovascular diseases and diabetes are the two main therapeutic fields that will be impacted by environmental risks, with two primary indicators: transient ischemic attacks and type 1 diabetes. Respiratory indicators such as chronic obstructive pulmonary disease (COPD) and asthma are also heavily affected by environmental risks.
36The scientific data can be used, for example, to inform R&D choices and predict necessary changes in the development and availability of health solutions. It is essential for healthcare and policymaking actors to incorporate environmental health data into their strategic decision-making.
37Furthermore, using new technologies (artificial intelligence and real-world evidence) to improve predictions about how climate change will impact patients and health systems is required, not only to help guide policymakers in the construction of health policies and improve how diseases are anticipated and controlled, but also to highlight the importance of making targeted investments in actions to ramp up adaptation and boost resilience.
38Since 2023, Sanofi has been working with a panel of experts in respiratory diseases on a major study to identify the impacts of environmental factors (temperatures, air pollution, soil composition, etc.) on the exacerbation of case of COPD and asthma in France. The study cross-references real-world data from the French health system (PMSI) with publically available data on climate factors. The resulting correlations will point to the extent to which exposure to different environmental factors influences the risks of exacerbating chronic respiratory diseases, and allow forecasts of current and future impacts on the saturation of health systems depending on how climate change evolves.
Figure 2: The role of health stakeholders

Source: Healthcare Without Harm, WHO, academic literature, BCG analysis.
39This type of study can improve knowledge sharing and research in a domain that remains under explored, improve prevention among groups who are potentially the most impacted or risk becoming impacted, and strengthen health structures. Towns and cities might also find this type of data of interest for their urban planning.
Coordinating the acceleration of collective action
40Health systems must become more aware of the importance of embedding recognition of the environmental value of health products and care pathways and the need to invest in prevention while also ensuring that progress toward meeting environmental targets does not compromise the prospects of achieving better outcomes for patients.
41This is not something that can be achieved by any one organization or a one-size-fits-all strategy. Health systems are complex and all stakeholder groups, each with a specific role to play, must be involved in designing and adopting innovative and sustainable solutions.
Conclusion
42The effects of climate change have a major influence on our living environment and our health. Extreme climate events (heat waves, floods, etc.) have well-known impacts on societies and overall environmental deterioration, leading to air and water pollution, food insecurity, the occurrence of vector-borne diseases, as well as an increase in the prevalence and severity of existing diseases. Many inequalities exist with regards to the impacts of climate change, requiring targeted action to assist vulnerable groups.
43The level of action being taken by health industry professionals is unprecedented. In addition to their commitments to reducing their own emissions, they are actively engaging with stakeholders in health systems to educate, raise awareness and promote the sharing of best practices, data and even technical skills by issuing recommendations and assessment guidelines.
44There is still enough time left for the world’s economy to make a decisive reduction in emissions and adopt strategies to protect human health against the impacts of climate change. It is however imperative that policymakers recognize and address the currently inadequate level of preparation of health systems.
Notes
1 Office of the United Nations High Commissioner for Refugees (2023). Climate change and displacement: the myths and the facts. UNHCR. https://www.unhcr.org/news/stories/climate-change-and-displacement-myths-and-facts.
2 World Economic Forum (2024). Quantifying the impact of climate change on human health. World Economic Forum. https://www.weforum.org/publications/quantifying-the-impact-of-climate-change-on-human-health.
3 M. Romanello, A. McGushin, C. Di Napoli C et al., Lancet 398(10311): 1619-62, The 2021 Report of The Lancet Countdown on Health and Climate Change: Code Red for a Healthy Future, The Lancet, vol. 398, no. 10311, pp. 1619-62, 2021.
4 Earthzine (June 28, 2011). Code Grey: Protecting Hospitals from Severe Weather. https://earthzine.org/code-grey-protecting-hospitals-from-severe-weather-2/.
5 Seltenrich, N. (2018). Safe from the storm: Creating climate-resilient healthcare facilities. Environmental Health Perspectives, 126(10). https://doi.org/10.1289/EHP3810.
6 Nair P. (August 29, 2018). Kerala floods: Health directorate estimates Rs110 crore loss. Kochi News – Times of India.
7 French Ministry of Health and Solidarity (2023). Presentation of the PESS program: priority on Prevention, Environment, Health and Health security. https://sante.gouv.fr/IMG/pdf/dp_pess.pdf.
8 Real-world data is information that is not collected as part of an experiment but when patients receive treatment, reflecting actual practices.
9 Hudson R et al. (December 2023). Assessing the Carbon Intensity Profile of an Immunization Program Against RSV in Infants in the United Kingdom to Show the Reduction in Emissions Versus Standard of Care, Value in Health, Volume 26, Issue 11, S2.
10 Intergovernmental Panel on Climate Change. (2023, March 20). Sixth assessment report: Synthesis report. https://www.ipcc.ch/report/sixth-assessment-report-working-group-ii/.
11 For more information, visit the DCarbon website, Sanofi’s partner for the study - https://dcarboneg.com/cop27side-events/accelerating-healthcare-de-carbonization/.
12 Sanofi (June12, 2024). The Link Between Climate and Health: We Chart a New Course https://www.sanofi.com/en/magazine/social-impact/climate-health-new-course.
Top of pageList of illustrations
![]() |
|
---|---|
URL | http://journals.openedition.org/factsreports/docannexe/image/7793/img-1.jpg |
File | image/jpeg, 176k |
![]() |
|
Title | Figure 1: 7 levers to reduce emissions in care pathways |
URL | http://journals.openedition.org/factsreports/docannexe/image/7793/img-2.png |
File | image/png, 80k |
![]() |
|
Title | Figure 2: The role of health stakeholders |
Credits | Source: Healthcare Without Harm, WHO, academic literature, BCG analysis. |
URL | http://journals.openedition.org/factsreports/docannexe/image/7793/img-3.png |
File | image/png, 118k |
![]() |
|
URL | http://journals.openedition.org/factsreports/docannexe/image/7793/img-4.jpg |
File | image/jpeg, 178k |
References
Bibliographical reference
Sandrine Bouttier-Stref, “Ensuring the resilience of health systems in the face of the effects of climate change”, Field Actions Science Reports, Special Issue 27 | 2025, 94-99.
Electronic reference
Sandrine Bouttier-Stref, “Ensuring the resilience of health systems in the face of the effects of climate change”, Field Actions Science Reports [Online], Special Issue 27 | 2025, Online since 15 December 2024, connection on 12 February 2025. URL: http://journals.openedition.org/factsreports/7793
Top of pageCopyright
The text only may be used under licence CC BY 4.0. All other elements (illustrations, imported files) are “All rights reserved”, unless otherwise stated.
Top of page