Climate Warming Accelerates Spread Of Antibiotic Resistance In Soils: Study
Study raises fresh concerns for India where rising temperatures, antibiotic misuse and environmental contamination pose a growing public health challenge, reports ETV Bharat’s Gautam Debroy.
Published : May 9, 2026 at 7:26 PM IST
|Updated : May 11, 2026 at 4:44 PM IST
New Delhi: A new scientific study has revealed that climate warming could accelerate the spread of antibiotic resistance in soils, raising fresh concerns for countries like India where rising temperatures, antibiotic misuse and environmental contamination already pose a growing public health challenge.
The study conducted by 24 renowned scientists and researchers found that long-term warming increased the abundance of antibiotic-resistance genes (ARGs) in grassland soils by nearly 24 per cent.
Scientists say the findings provide some of the strongest evidence yet that climate change itself may become a major driver of antimicrobial resistance (AMR), a crisis already projected to cause up to 10 million deaths annually worldwide by 2050 if left unchecked. The study was published in scientific and medical journal Nature.
“Rise in the environmental temperature is known to be associated with anti-microbial resistance or AMR, a situation where bacteria or other microorganisms are no longer treatable with existing antibiotics and similar agents. The mechanism is genetic, and such antibiotic resistance genes can even be transferred from one bacteria to the other. There are many factors contributing to antibiotic resistance in bacteria, including exposure to widespread antibiotic use by man, exposure to heavy metals in the soil and rise in temperature,” renowned health expert and convener of the Indian Medical Association (IMA’s) research cell Dr Rajeev Jeyadevan told ETV Bharat on Saturday.
“There are many factors contributing to antibiotic resistance in bacteria, including exposure to widespread antibiotic use by man, exposure to heavy metals in the soil and rise in temperature.”
Higher Temperatures Selectively Favour Heat-tolerant Bacteria
The research showed that higher temperatures selectively favoured heat-tolerant bacteria, especially Actinomycetota, a group of bacteria known for naturally producing antibiotics and carrying resistance genes. As these microbes became more abundant in warming soils, the overall concentration and mobility of ARGs also increased.
Researchers observed particularly sharp increases in glycopeptide- and rifamycin-resistance genes. More importantly, warming enhanced horizontal gene transfer, allowing resistance traits to move more rapidly between bacteria.
“Steady rise in average temperature is now being seen across the world, and India is no exception. While climate change is not an easily modifiable risk factor, it is important to take proactive steps so that many years down the line, hopefully we can reduce the impact of climate change. Meanwhile, other steps to control antimicrobial resistance must be continued such as avoiding unnecessary antibiotic use, promoting safe disposal of antibiotics in the environment, controlling the use of veterinary antibiotics, implementing proper antibiotic use policy in hospitals, preventing self-medication with antibiotics by individuals and restricting the sale of antibiotics to only those who have a valid prescription,” said Dr Jeyadevan who is also the co-chairman of the national IMA Covid Task Force.
He said that antibiotic resistance found in bacteria that live in the soil will find its way to human beings in multiple ways. These bacteria interact with crops and can transfer their genes to the bacteria found in the plant root systems.
“Bacteria in farmland can enter the human body by consumption. Bacteria can also transfer resistance genes to other bacteria, which may eventually enter the human body either through water or food supply. Therefore, environmental antimicrobial resistance indirectly contributes to disease in man,” said Dr Jeyadevan.
What Makes India Highly Vulnerable
The study’s findings are being viewed as highly relevant for India, where tropical climatic conditions, dense population, antibiotic overuse, untreated wastewater and agricultural contamination already create ideal conditions for the spread of resistant microbes.
Talking to ETV Bharat, renowned microbiologist Dr Ashok Rattan said the study successfully connects climate change with microbial evolution and environmental transmission pathways of resistance.
“We already know that bacterial resistance can either be intrinsic or acquired after exposure to antibiotics. Some bacteria naturally possess resistance because they themselves produce antibiotics. These bacteria carry resistance genes from the beginning in order to protect themselves,” Dr Rattan explained.
He said the overuse of antibiotics in humans and animals creates selective pressure that allows resistant bacteria to survive while sensitive bacteria die.
“If you keep giving the same antibiotic repeatedly, resistant bacteria gain an advantage and proliferate. That is why antimicrobial resistance has become such a major global problem,” he said.
According to Dr Rattan, the new study is particularly significant because it demonstrates how warming itself can increase mutation frequency and select resistant organisms over long periods.
“This is one of the first studies to document that when temperatures rise by about 3°C over many years, mutation frequency increases and resistance selection becomes stronger,” said Dr Rattan who deals with evidence-based medicine, laboratory diagnosis, IVD (in vitro diagnostics) development and taking essential diagnosis to the last mile.
India’s environmental conditions could make the threat even more serious. Dr Rattan noted that warmer countries naturally support larger populations of actinomycetes and other heat-tolerant microbes linked to antibiotic production and resistance.
“In India, you will find far more actinomycetes than in colder regions like Scotland. When temperatures rise further, these bacteria get a selective advantage because they are better adapted to survive heat,” said Dr Rattan who also worked as a faculty member at Delhi-AIIMS.
The paper (the Nature study) is essentially saying that climate warming selects bacteria capable of surviving heat, and those same bacteria often carry resistance genes, Dr Rattan said.
Scientists warn that the environmental spread of resistance genes may eventually affect human health through food chains, water systems and direct exposure.
“The bacteria in soil may not at all directly infect humans. But resistance genes can jump from harmless environmental bacteria into pathogenic bacteria through horizontal gene transfer,” Dr Rattan said. “Then through food, water and environmental exposure, humans become vulnerable to resistant infections.”
Significance Of 'One Health' Approach
Experts say the findings reinforce the importance of the “One Health” approach, which links human health with animal and environmental health.
“You cannot protect human health without protecting animal health, and you cannot protect either without protecting soil and environmental health,” Dr Rattan emphasised.
India has already been battling one of the world’s highest burdens of antimicrobial resistance. Public health studies have repeatedly shown widespread misuse of antibiotics in human medicine, poultry farming and livestock sectors. Antibiotics are often available without prescriptions in many areas, while untreated pharmaceutical waste and sewage continue entering rivers, lakes and agricultural soils.
Dr Rattan pointed out that antibiotic residues in the environment further intensify resistance selection. “Many antibiotics given to humans are not completely metabolised. They enter wastewater and then the soil. So now the environment is continuously exposed to low concentrations of antibiotics. Heat is now becoming an additional selective pressure,” he said.
The study therefore highlights a dangerous convergence between climate change and environmental contamination. “This paper links everything together — soil, food, wastewater, climate and human health,” Dr Rattan said.
The study also raises concerns for Indian agriculture because soils serve as critical reservoirs of bacteria that interact with crops, livestock and water systems. Resistant microbes in agricultural soil could affect food safety and livestock productivity while increasing the risk of resistant infections among rural populations.
Dr Rattan said stronger environmental policies are urgently needed alongside antibiotic stewardship programmes.
“For example, composting is beneficial because the heat generated during composting kills many bacteria. Wastewater treatment is also critical because untreated sewage carries both antibiotics and resistant bacteria into the environment,” he said.
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