Climate Pressure Is Accelerating Antimicrobial Resistance Across Human and Animal Health
Climate change is now part of the biology of antimicrobial resistance, not just the background to it. Rising temperatures, shifting rainfall, ecosystem disruption, and more frequent extreme weather events are expanding the conditions in which resistant bacteria, zoonotic pathogens, and vector-borne infections can spread. The result is a self-reinforcing cycle: more infection leads to more antibiotic use, and more antibiotic use increases the chance that resistant organisms will be selected and maintained.
The review places antimicrobial resistance and climate change in the same causal frame. That is a meaningful shift from older approaches that treated resistance as a prescribing problem alone. Environmental stressors alter pathogen ecology, animal reservoirs, water systems, and human exposure patterns at the same time. Once those pressures converge, the clinical burden does not stay confined to hospitals; it moves through communities, food systems, and veterinary settings as well.
A central biological concern is that bacterial resistance often does not carry a major fitness cost. Resistant organisms can persist even when antibiotic pressure eases, which makes prevention far more valuable than trying to reverse resistance after it has become entrenched. In practice, this means climate-related infection surges are not temporary inconveniences. They can leave behind a more durable microbial population structure that is harder to treat across multiple settings.
Infection Burden, Antibiotic Use, and the Selection Pressure That Follows
The path from climate change to AMR is indirect but clinically intuitive. Warming temperatures and disrupted ecosystems raise the incidence of infectious diseases, and each additional infection episode increases the probability of antibiotic exposure. More prescriptions, more empiric treatment, more prophylaxis in vulnerable settings, and more pressure in agriculture all strengthen the ecological advantage of resistant strains.
This matters most in regions already operating near the edge of capacity. Low- and middle-income countries face the steepest climate vulnerability while also living with thinner health infrastructure, weaker surveillance, and more limited access to diagnostic testing. In those settings, clinicians often have fewer options to confirm bacterial versus viral disease, which can drive broader antibiotic use and weaken stewardship efforts. The clinical consequences are amplified by shortages in sanitation, clean water, and resilient supply chains for essential medicines.
The review argues that climate-sensitive infectious disease control and AMR control are inseparable. Febrile illness outbreaks after floods, heat-related shifts in vector habitats, and expanding zoonotic interfaces all create new opportunities for antibiotic overuse. At the bedside, this translates into more uncertainty, earlier empiric therapy, and a greater chance that treatment is misaligned with the underlying pathogen.
Resistance thrives when the system is forced to practice medicine under environmental strain.
Why Low- and Middle-Income Countries Carry the Heaviest Clinical Burden
The disproportionate impact on LMICs is not simply a matter of geography. It reflects a collision between higher climate exposure and weaker health systems. When flooding damages sanitation networks, or heat stress increases infection risk, the downstream effects are felt first in communities with limited laboratory capacity, inconsistent drug access, and constrained public health response. Resistant pathogens can then move faster than formal surveillance systems can track them.
Economic consequences follow quickly. More severe infection outbreaks mean more hospital visits, longer stays, higher medication costs, and greater demand for already stretched staffing and infrastructure. For households, the burden can be catastrophic; for governments, it can erode the ability to fund prevention, diagnostics, and stewardship. In that setting, AMR becomes both a medical problem and a development problem.
The review’s public health message is blunt: climate adaptation plans that ignore resistance will miss a major driver of future infectious disease burden. Likewise, antibiotic stewardship programs that ignore climate and environmental exposures will be working with only part of the causal chain.
Pandemic Disruptions Exposed How Quickly the Environment Responds to Human Activity
The review draws on pandemic-era environmental changes to illustrate how quickly ecological conditions can shift. Temporary reductions in nitrogen dioxide emissions were observed during COVID-19 restrictions, including declines of 20% to 30% in China, Italy, France, and Spain, and about 30% in the USA. Those figures are not presented as a solution, but they show that human activity can rapidly alter the atmospheric and environmental forces that shape disease transmission and exposure.
The clinical relevance is broader than air quality alone. Environmental shifts can influence mobility, settlement patterns, vector distribution, agricultural productivity, and access to care. Each of those factors feeds into the infection landscape that determines how often antibiotics are prescribed and how often resistant organisms gain an advantage. The pandemic also exposed how fragile global health systems can become when routine surveillance, prevention, and care pathways are interrupted.
A One Health Response Needs Surveillance, Stewardship, and Cross-Sector Coordination
The review makes the case for a One Health framework because the threat is already cross-sectoral. Human medicine, veterinary care, agriculture, environmental policy, and public health cannot operate in silos if the goal is to reduce both infection pressure and resistant selection. The quadripartite partnership of FAO, UNEP, WHO, and WOAH is presented as the central coordinating structure for that work.
Surveillance sits at the center of the strategy. Tracking resistant organisms in humans, animals, food systems, and environmental reservoirs would make it easier to identify climate-linked hotspots before outbreaks spread. Antibiotic stewardship remains essential, but stewardship alone cannot compensate for the broader environmental drivers that increase disease incidence in the first place. Prevention, sanitation, vaccination where available, diagnostic capacity, and resilient health systems all become part of the resistance agenda.
A coordinated approach also has a practical bedside consequence: fewer infections means fewer empiric antibiotics, and fewer empiric antibiotics means less selection pressure for resistant bacteria. That is the simplest biological equation in the paper, and also the most important one. If climate change continues to intensify infection burden, every delay in integrated action raises the probability that routine infections will become harder to treat.
Integrated Prevention Is the Only Credible Way to Slow the Dual Threat
The review does not argue for a single intervention. It argues for an integrated response because the causality is layered. Climate change alters exposure, exposure increases infection, infection increases antibiotic use, and antibiotic use selects resistance. Breaking that chain requires coordinated action at multiple points rather than a narrow focus on treatment failure after resistance has already emerged.
The most immediate policy implication is that climate adaptation and AMR mitigation should be designed together. Health systems need stronger surveillance, better diagnostics, cleaner water and sanitation, improved infection prevention, and stewardship programs that are realistic for resource-limited settings. Agricultural and environmental policy matter too, because resistant organisms do not respect institutional boundaries.
The article’s final message is grounded in urgency rather than optimism: climate change and AMR are interconnected crises that will keep feeding one another unless global health systems treat them as a single problem with shared drivers, shared surveillance needs, and shared solutions.