Antimicrobial resistance (AMR) is progressively undermining one of the foundations of modern medicine. Infections that were once readily treatable are becoming more difficult, costly, and sometimes impossible to manage, threatening not only the treatment of infectious diseases but also surgery, cancer care, organ transplantation, intensive care, and many other medical interventions that depend on effective antimicrobials. At the same time, another global crisis is reshaping the conditions in which infectious diseases emerge and spread: climate change.
These threats are often addressed separately. AMR is discussed primarily within infectious diseases, microbiology, antimicrobial stewardship, and health-system policy, while climate change is approached through environmental, energy, and sustainability agendas. Yet the boundaries between them are increasingly difficult to defend. Rising temperatures, extreme weather events, changing ecosystems, population displacement, water scarcity, and disruptions to sanitation can alter the transmission, survival, and geographic distribution of pathogens and antimicrobial-resistant microorganisms. Climate change does not simply coexist with AMR. It can create conditions in which resistance becomes more difficult to prevent, detect, and control.
The connection becomes particularly visible during climate-related emergencies. Floods can overwhelm sewage and sanitation infrastructure, contaminate water sources, damage healthcare facilities, and facilitate the dissemination of pathogenic and resistant microorganisms. Droughts and water scarcity can compromise hygiene and sanitation while increasing dependence on unsafe water sources. Extreme weather events can disrupt healthcare delivery, laboratories, supply chains, infection-prevention programmes, and surveillance precisely when populations become more vulnerable to infectious diseases.
Temperature itself may also matter. Changes in temperature and humidity influence microbial growth, environmental persistence, host-pathogen interactions, and infectious-disease ecology. As climatic conditions change, the geographic distribution and seasonality of some infectious diseases may also shift, exposing new populations and health systems to unfamiliar threats. Increased infectious-disease burden can, in turn, increase demand for antimicrobial treatment. Where diagnostic capacity is limited, this may lead to greater empirical or inappropriate antimicrobial use, increasing selective pressure and potentially accelerating resistance.
The relationship is therefore both ecological and clinical. Climate change can influence where pathogens circulate and how populations are exposed to them, while simultaneously weakening the health and public-health systems responsible for responding to infection. The greatest effects are likely to be felt where these systems are already fragile.
This raises an unavoidable issue of global health equity. The populations most vulnerable to climate change are frequently those with the fewest resources to adapt to it. Many of the same communities also face inadequate access to clean water, sanitation, microbiological diagnostics, infection prevention and control, surveillance, quality-assured antimicrobials, and healthcare. Climate vulnerability and AMR vulnerability can therefore overlap, creating a dangerous convergence in which infectious-disease risk increases while the capacity to diagnose and treat infections deteriorates.
Yet the relationship between AMR and the environment does not operate in only one direction. Antimicrobial use itself has an environmental dimension. Antibiotic residues, resistant bacteria, and resistance genes can enter ecosystems through human and animal waste, healthcare facilities, agriculture, aquaculture, wastewater, and pharmaceutical manufacturing. Where wastewater treatment and environmental regulation are inadequate, these pathways can contribute to environments in which antimicrobial resistance is selected, maintained, and disseminated.
The healthcare response to resistant infections also carries an environmental footprint. Patients with difficult-to-treat infections may require longer hospital stays, additional diagnostic investigations, more complex antimicrobial regimens, isolation procedures, and greater use of healthcare resources. Hospitals themselves are resource-intensive environments, consuming substantial amounts of energy, water, pharmaceuticals, and disposable materials. AMR and environmental sustainability should therefore not be viewed as unrelated agendas. A health system that prevents infections and uses antimicrobials appropriately can simultaneously reduce unnecessary antimicrobial exposure, healthcare utilisation, and environmental burden.
This interconnectedness is precisely why a One Health perspective is essential.
Human health, animal health, and environmental health are not independent domains. Humans, animals, microorganisms, food systems, water, and ecosystems are components of the same biological and ecological network. Resistant organisms and resistance genes can move within this network, just as climate-driven environmental changes can alter the conditions governing infectious-disease transmission. Policies that address only one part of this system will inevitably overlook important pathways through which risk is generated and amplified.
One Health, however, must become more than a conceptual framework repeatedly invoked in policy documents. It must translate into practical integration. Climate adaptation strategies should explicitly consider infectious-disease risks and AMR. National AMR action plans should incorporate environmental and climate-related vulnerabilities. Antimicrobial stewardship should be connected to infection prevention, vaccination, water and sanitation, environmental management, and sustainable healthcare. Agricultural and veterinary policies should recognise their implications for both resistance and environmental health.
Surveillance will be central to this integration. Traditional surveillance systems often remain fragmented across human health, veterinary medicine, agriculture, food systems, and the environment. Yet emerging threats do not respect these administrative boundaries. Integrated surveillance capable of detecting changes in pathogens, antimicrobial resistance, antimicrobial consumption, environmental contamination, and climate-sensitive disease patterns could provide earlier warning of changing risks. Strengthening microbiology laboratories and diagnostic capacity is equally important, particularly in resource-constrained settings where empirical antimicrobial treatment remains common because clinicians lack timely diagnostic information.
Investment in basic infrastructure may provide some of the greatest shared benefits. Safe water, sanitation and hygiene reduce infectious-disease transmission and the need for antimicrobial treatment while simultaneously strengthening resilience to climate-related disruption. Effective wastewater treatment can reduce environmental dissemination of pathogens, antimicrobial residues, and resistant organisms. Vaccination can prevent infections and reduce antimicrobial consumption. Strong infection prevention and control can limit transmission in healthcare facilities. Resilient hospitals can continue providing essential services during floods, heatwaves, storms, and other climate-related emergencies.
These are not isolated interventions. They represent opportunities to address several dimensions of health security simultaneously.
The same principle applies to food systems. Sustainable agriculture, responsible antimicrobial use in animals, improved biosecurity, surveillance, and environmental protection can contribute to reducing both ecological vulnerability and antimicrobial resistance. The objective should not be to create separate climate, AMR, food-security, and health-security programmes competing for limited resources, but to identify interventions capable of producing benefits across these interconnected priorities.
Most importantly, the global community must resist the temptation to act only when these challenges become emergencies.
Climate change and AMR share a particularly dangerous characteristic: both are slow-moving crises punctuated by sudden shocks. Their progression can appear gradual enough to tolerate delay, yet their consequences accumulate continuously. A resistant organism spreads unnoticed until treatment fails. Environmental conditions change incrementally until an outbreak occurs. Infrastructure deteriorates until an extreme weather event exposes its fragility. Political attention, meanwhile, is often captured by immediate crises rather than by the structural vulnerabilities that make those crises possible.
Prevention therefore requires acting before consequences become irreversible. Waiting for antimicrobial resistance to eliminate therapeutic options before investing in stewardship, diagnostics, infection prevention, and new treatments is no more rational than waiting for climate-related disasters before investing in resilient infrastructure. In both cases, delayed action ultimately increases human and economic costs.
There is also a broader lesson for global health. The major threats of the coming decades are unlikely to fit neatly within traditional disciplinary boundaries. Climate change, AMR, emerging infections, food insecurity, environmental degradation, migration, and health-system fragility interact in ways that can amplify their individual effects. Responding to each through isolated programmes risks repeatedly treating consequences while leaving the systems that generate vulnerability unchanged.
The future of global health will therefore depend on our capacity to replace fragmented responses with systemic thinking. This does not mean collapsing climate policy and AMR policy into a single agenda. Their causes, mechanisms, and solutions remain distinct in important ways. It means recognising where they intersect and ensuring that interventions in one domain reinforce rather than undermine progress in another.
AMR and climate change are among the defining global health challenges of our time. Neither respects national borders nor can be solved by the health sector alone, and both disproportionately affect populations with the fewest resources to protect themselves. Their convergence should compel us to rethink how health security, environmental sustainability, and development are connected.
AMR and climate change are not simply two global threats competing for political attention. They are interconnected manifestations of a changing world. Addressing them together is not only a scientific and public-health necessity; it is a test of whether we can develop the collective vision required to protect health in the decades ahead.
References
van Bavel B, Berrang-Ford L, Moon K, Gudda F, Thornton AJ, Robinson RFS, King R. Intersections between climate change and antimicrobial resistance: a systematic scoping review. Lancet Planet Health. 2024 Dec;8(12):e1118-e1128.
Baroja E, Batalla I, Sanz MJ, Chiabai A. An integrated framework for antimicrobial resistance: links with climate change and vulnerability. Front Public Health. 2026 Feb 3;13:1679189.
Author
Massimo Sartelli
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