Antimicrobial Resistance in a Changing Climate: Evidence, Causal Pathways, and Prevention Strategies

Abstract

Background: Antimicrobial resistance (AMR) and climate change are both significant global health threats increasingly recognized as mechanistically interconnected. This review critically synthesises evidence on the potential for climate-related hazards (temperature, heatwaves, flooding and drought) to alter and intensify AMR via biological, environmental and health-system pathways, and evaluates the causal strength and implications for prevention.

Methods: This critical narrative review involved a structured literature-identification and updating process, critically appraising systematic and scoping reviews, primary ecological and genomic studies, modelling analyses, and authoritative One Health reports through August 2026, organized by hazard and pathway rather than paper by paper.

Results: Association of temperature with AMR is one of the most consistent and replicated findings across ecological studies in the United States, Europe and China, and is supported by a large multi-country genomic analysis of Salmonella resistance genes. This relationship is not generalizable: at least one adjusted analysis found no significant temperature-resistance

association, highlighting the organism- and context-specific nature of the relationship. Resistant pathogens and resistance genes are mobilized in the environment during flooding, but there is limited direct evidence of this leading to increased clinical infection. Ecological study design, residual confounding and limited data availability in South Asia, including Pakistan, limit causal inference across hazards. Evidence assessing climate-specific AMR prevention interventions remains limited.

Conclusions: Climate change must be considered as a potential contributing and amplifying factor for AMR, rather than a proven independent cause. Climate-informed surveillance is a priority for LMICs, including Pakistan, for One Health AMR strategies.