Antimicrobial resistance (AMR) is one of the most pressing threats to global health and development. Recent projections indicate that between 2025 and 2050, AMR could directly cause over 39 million deaths worldwide, with annual deaths attributable to AMR expected to rise from 1.14 million in 2021 to 1.91 million by 2050. AMR poses a profound threat to lives, livelihoods, and ecosystems globally, with the poorest and most vulnerable populations bearing the heaviest burden. In low- and middle-income countries (LMICs), fragile healthcare systems, inadequate sanitation, and limited access to effective treatments amplify the impacts of AMR, leading to preventable deaths and prolonged hospital stays.
AMR also threatens food security and agricultural livelihoods as resistant infections spread through livestock and crops, undermining local economies. Environmental contamination with antibiotic residues further exacerbates the problem, disrupting ecosystems and facilitating the spread of resistance genes. Addressing AMR in these settings requires targeted interventions that integrate health, agriculture, and environmental strategies to protect the most at-risk populations.
Emerging evidence is also revealing the interplay between AMR and climate change, potentially intensifying the environmental drivers of resistance - rising temperatures and altered precipitation patterns can influence the spread of resistant pathogens and reduce the effectiveness of existing antimicrobial treatments.
Concurrently, the world faces an unprecedented displacement crisis. As of 2023, approximately 117.3 million individuals have been forcibly displaced due to violence, conflict, and persecution - a staggering 70% increase since 2018. Among these, one in four are vulnerable children under the age of twelve, and half are women and girls. Those living in unstable and conflict-ridden regions are particularly at risk from the relentless threats posed by climate change. Today, nearly 90 million displaced individuals find themselves in countries exposed to high to extreme climate-related risks. Alarmingly, almost half of all forcibly displaced persons are grappling with the dual challenges of conflict and the devastating impacts of a changing climate. Addressing these intertwined challenges necessitates urgent and comprehensive action.
Climate change as a catalyst for AMR?
The far-reaching effects of climate change have profoundly transformed our ecosystems and reshaped the intricate dynamics of microbial life. Over the past decades, the impact of climate change on public health has escalated alarmingly, with extreme weather events driving surges in excess deaths, hospitalizations, and crop yield declines. Experts predict an additional 250,000 fatalities annually between 2030 and 2050 due to climate-related health impacts. Evidence is emerging that climate change not only fosters the emergence of new pathogens, but also the re-emergence of “superbugs” driven by shifting temperatures.
Rising temperatures, intense rainstorms, and flooding exacerbate infections, displacing populations and spreading antimicrobial residues, creating optimal conditions for resistance to thrive. Notably, resistance in pathogens such as Escherichia coli and Klebsiella pneumoniae has been linked to rising temperatures, with resistance rates rising by approximately 10% with every 10°C temperature increase.
Further complicating the situation is antibiotic contamination from agricultural runoff, wastewater discharge, and pharmaceutical waste. This creates reservoirs for antibiotic resistance genes (ARGs) in freshwater systems and soils, compounding the risks to both environmental and human health. Wastewater has emerged as a particularly significant reservoir of ARGs, further accelerating the transmission of resistant pathogens across ecosystems.
Climate-adaptive agricultural practices, including the use of low-efficacy antibiotics in aquaculture, are inadvertently accelerating AMR by creating conditions ripe for the rapid diffusion and localized accumulation of resistance genes through food chains, increasing the risk of human exposure to resistant pathogens through consumption.
However, currently, there are still many gaps in our understanding of the interplay between these phenomena and the potential mutually reinforcing effects of climate change and AMR.
Conflict: a hidden driver of AMR?
Recent studies underscore conflict as a significant but often overlooked driver of AMR. War-related destruction of water and sanitation infrastructure, disrupted medical supply chains, and environmental contamination from heavy metals create conditions that foster resistant bacteria. In conflict zones such as Syria, Gaza, and Ukraine, frontline medical facilities face severe shortages, leading to the overuse of broad-spectrum antibiotics without adequate diagnostic support. Reports from Ukraine indicate that wound infections frequently involve multidrug-resistant Acinetobacter and Klebsiella, pathogens that may be carried beyond the conflict zones by evacuees and military personnel. Similar patterns are observed in Gaza, where shortages of effective antibiotics heighten infection risks for burn victims, exacerbating resistance.
According to Dr. Aula Abbara, a specialist in infectious diseases and humanitarian health, the drivers of AMR in conflict settings include:
“The breakdown of infection control and antibiotic stewardship programs due to attacks on healthcare and healthcare workers with simultaneous increases in demand due to an increase in traumatic injuries including contaminated or traumatic wounds in which prosthetic materials are used which are at greater risk of infection. This is compounded by damage to water infrastructure, a lack of diagnostics and interrupted supply chains and such that diagnosing, preventing and treating drug resistant infections becomes more challenging. “ - (Abbara et al., 2025)
Climate change compounds these issues by altering disease patterns, increasing the frequency of natural disasters, and straining already vulnerable health systems. These combined factors create environments where AMR can thrive, particularly among displaced populations lacking access to adequate healthcare.
Microbial insights - what research reveals
Microbiological research is indispensable in unravelling the complex connections between AMR and climate change, particularly through a One Health lens that integrates environmental, animal, and human health. Drawing from 4502 surveillance records from 101 countries and over 32 million microbial isolates from 1999-2022, the evidence reveals the compounding effect of rising ambient temperatures, heavy and prolonged rainfall, droughts, and surface runoffs, coupled with socioeconomic inequalities and consequences of AMR prevalence. Climate-related environmental factors directly correlate with increased resistance in pathogens such as Acinetobacter baumannii and Escherichia coli, especially in warm, flood-prone areas. Surveillance efforts in China uncovered colistin-resistant E. coli in pigs and raw meat, alongside Salmonella in eggs, underscoring the importance of comprehensive monitoring from farm to fork. Such evidence emphasizes the need for enhanced surveillance and targeted interventions, particularly in monitoring these dynamics, identifying emerging resistance hotspots, and informing targeted interventions. Key drivers of AMR include not just antimicrobial consumption but also insufficient health investment, high out-of-pocket healthcare costs, and poor access to water, sanitation, and hygiene (WASH).
Under worst-case climate scenarios, with AMR projected to rise by 22.3% in LMICs, climate-related pressures, rising temperatures, flooding, habitat loss, and shifting ecological interactions only exacerbate microbial gene transfer and resistance dissemination. They also silently erode drug discovery pipelines rooted in nature. These environmental changes affect the phytochemical profiles of medicinal plants, host-pathogen responses, and human adaptations, potentially reducing their antimicrobial efficacy or, worse, enhancing resistance selection pressures.
Multidisciplinary context-specific microbial research is essential to develop effective, evidence-based strategies to manage AMR, especially in the context of the pressures exerted by climate change, especially in conflict zones.
Bridging disciplines & policy responses
In September 2024 at the 79th United Nations General Assembly, world leaders adopted a landmark Political Declaration on AMR, reaffirming their commitment to addressing AMR. The declaration sets ambitious targets, including a 10% reduction in global deaths associated with AMR by 2030, from the 2019 baseline of 4.95 million deaths. Recognizing the interconnectedness of human, animal, and environmental health, the declaration emphasizes a One Health approach. It urges the reduction of antimicrobial use in agri-food systems and the implementation of animal vaccination strategies to decrease reliance on antimicrobials. Additionally, the declaration highlights the need to prevent and address the discharge of antimicbobials into the environment, calling for increased research and knowledge on the environmental dimensions of AMR.
The mandate was also received to establish an Independent Panel on Evidence for Action Against AMR, to:
“…facilitate the generation and use of multisectoral, scientific evidence to support Member States in efforts to tackle antimicrobial resistance, making use of existing resources and avoiding duplication of on-going efforts, after an open and transparent consultation with all Member States on its composition, mandate, scope, and deliverables.” - (UN 2024)
Leveraging existing knowledge and resources, plus much-needed new data, this new Panel is set to play a pivotal role in guiding evidence-based policy development, implementation, and accountability. Strategic tools to shape and drive the policy response to address AMR effectively will also be needed. A recent publication outlines one such approach - ‘The AMR Cube’, based on the ’Universal Health Coverage Cube’ - to support the identification of existing policy gaps, and the prioritizing and implementation of comprehensive, multisectoral interventions to address AMR effectively.
Learning lessons from different sectors and stakeholders will be key. This includes strengthening collaboration with climate scientists to help further explore the emerging climate-AMR nexus, leveraging a robust data foundation and perspectives with the potential to develop AMR metrics and interventions that are climate-resilient.
Conclusion
Research plays a vital role in advancing targeted interventions, from developing therapeutics and rapid diagnostics to mapping resistance hotspots influenced by climate change. The 2024 Political Declaration on AMR underscores the need for a One Health approach, emphasizing cross-sector collaboration to reduce antimicrobial use, enhance surveillance, and mitigate environmental risks. However, transforming policy into impact demands multidisciplinary research to inform climate-sensitive/ resilient health strategies. Coordinated and prioritised efforts across research, policy, and public health are essential to mitigate AMR’s escalating impact, protect the most vulnerable populations, and address the complex drivers of AMR globally.
Many thanks to Dr. Jomana Musmar and Dr. Aula Abbara for catalyzing cross-sectoral thinking and policy engagement on this topic of climate, conflict, and antimicrobial resistance.
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