Climate Change Accelerates Global Spread of Antibiotic Resistance, Study Reveals

Climate change is driving a worldwide increase in antibiotic resistance, posing a critical threat to human health, experts warn. New figures reveal a rise in antibiotic-resistant salmonella genes, according to recent research.

Antibiotic resistance ranks among the fastest-growing threats to global health. The condition affects individuals across all ages and nations, and currently kills over 1 million people annually, according to estimates.

A landmark study involving researchers from the UK, France, Australia, Switzerland, and China has uncovered how climate change is contributing to rising antibiotic resistance in salmonella, one of the world’s most common bacterial diseases.

The analysis shows a 10% global increase in salmonella antibiotic resistance genes between 1940 and 2023, marking the first comprehensive study of its kind published in The Lancet Planetary Health journal.

While antibiotic misuse and overuse remain the primary drivers of resistance, this research indicates climate change is exacerbating the problem. “The accumulating evidence suggests that climate change acts as an accelerating force behind the global spread of antimicrobial resistance,” the study authors wrote.

The findings demonstrate that rising temperatures and shifting precipitation patterns non-linearly amplify the abundance and transmission of antimicrobial resistance genes in bacterial pathogens like salmonella.

“These results underscore how climate change disrupts microbial ecological stability and accelerates resistance evolution across human, animal, and environmental reservoirs,” the researchers noted.

The study emphasizes that integrating climate change mitigation policies—particularly those aligned with the Paris Agreement—with enhanced antimicrobial stewardship and One Health surveillance is crucial to reducing future antimicrobial resistance burden.

Antimicrobial resistance primarily stems from antibiotic overuse, allowing resistant bacteria to survive and spread. However, rising temperatures and changing rainfall patterns influence bacterial survival, mutation, and transmission, potentially increasing antibiotic resistance gene exchange.

Previous research linked higher temperatures to increased resistant bacteria, but global quantitative studies have been limited until now. This new study analyzed over 480,000 salmonella genomes from 139 countries collected between 1940 and 2023, comparing resistance gene levels with temperature and rainfall changes over time.

The researchers found that resistance doesn’t increase steadily with rising temperatures; instead, resistance gene counts fluctuate in complex ways influenced by both temperature and rainfall.

This indicates that environmental changes accelerate bacterial adaptation to antibiotics.

The study revealed that 82% of countries showed increases in salmonella antibiotic resistance genes, with the strongest climate-linked increases in the Middle East, North Africa, South Asia, and sub-Saharan Africa.

While the study identified a correlation between climate change and antibiotic resistance genes in salmonella, it did not establish direct causation. Nonetheless, the authors stress that climate change must be factored into global antibiotic resistance mitigation efforts.

Immediate action—complemented by responsible antibiotic use and improved disease surveillance—is essential to limit future resistance spread.

The research provides “robust evidence” linking climate change to elevated antibiotic resistance risk, emphasizing that combining climate mitigation with antimicrobial stewardship could effectively curb resistance gene dissemination.

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