‘India’s Vital Efforts to Tackle Air Pollution Could Worsen Warming’
‘If India Chokes Less, It Will Fry More’
‘Controlling Air Pollution May Increase India's Temperatures’
Attention-grabbing headlines like these have been circulating in recent months, sparking considerable confusion — the latest appearing in The Economist on 28 May.
The gist of it is that over the years, South Asia has warmed far more slowly than much of the rest of the world. According to the United States’ National Aeronautics and Space Administration (NASA), global temperatures have risen by at least 1.1°C since 1880, with most of the warming since 1975 at about 0.15 – 0.20°C per decade. In contrast, South Asia has warmed by just 0.09°C per decade.
One leading theory is that smog and high levels of air pollution may be playing a cooling role by blocking sunlight.
These articles also cite a study from November 2024 that says that cleaning up the air, could potentially trigger a spike in warming across the region.
But scientists speaking to The Quint are cautious about the pollution hypothesis and warn against drawing quick conclusions without stronger evidence — especially given that sensational headlines that present only part of the picture can mislead the public and distort the larger climate conversation.
What Is the South Asian 'Warming Hole’ Theory?
Scientists have long been puzzled by the unusually slow rate of warming in South Asia compared to the rest of the world. One theory points to high aerosol levels in this region, which are believed to suppress local temperatures.
Aerosols are tiny particles in the air — including water droplets, sulphates, carbon particles, and other fine particulate matter. “This is what creates the masking effect,” says Abhiyant Tiwari, Lead Climate Resilience and Health Consultant at NRDC India.
Anjal Prakash, Research Director at the Bharti Institute of Public Policy, Indian School of Business, further explains. “There’s some evidence that India’s extreme air pollution, particularly aerosol-like sulfates and black carbon, may be masking the full impact of global warming by forming a reflective layer that bounces sunlight away and cools the Earth’s surface. This gives rise to the idea of India being a global warming 'hole,' where temperatures have risen more slowly than the global average.”
While this theory is plausible, Prakash and other experts underscore that it remains highly debated. They go on to add that the actual impact of this effect on regional heat is likely minimal.
No Silver Lining to Air Pollution?
Even as aerosols could provide a masking effect by reflecting sunlight to some extent, "air pollution doesn't just have aerosols, but also includes gases like methane and carbon monoxide that contribute to the greenhouse effect by trapping heat," says Sahana Hegde, agro-meteorologist with nearly a decade of experience in weather advisories, climatology, and future climate projections.
"Some research also shows that aerosols can create the conditions for water vapour accumulation and suspension in the air, which actually increases the temperature of the air."Sahana Hegde
This is why many scientists remain apprehensive about the theory that air pollution is significantly slowing warming.
"The science is still evolving, and there isn't much consensus on this. Some researchers argue that cooling effect is overstated and highly localised which is clear in the paradox of pollution in India that is killing people today. It may be temporarily delaying the climate crisis but it is in the horizon," says Anjal Prakash.
Even The Economist article acknowledges this uncertainty, stating, “There is no scientific consensus on how much these factors have slowed warming in South Asia... In the coming decades, neither pollution nor irrigation will continue to grow as both have over the past 40 years. They conceal additional warming only as long as their levels are increasing..."
"In India, average temperatures have been rising steadily, with each year setting new records for heat. The increasing frequency and intensity of extreme heat events have been crossing critical thresholds known as thermal danger zones, posing serious health risks. So, a few decimal points of difference in rate of warming doesn't make any difference when you look at the bigger picture, especially when it comes at the cost of dirtier air."Abhiyant Tiwari
One thing scientists agree on is that this anomaly is unlikely to be caused by a single factor — it’s more likely the result of a complex interplay of multiple, cascading influences, and more scientific assessment is needed to understand this phenomenon fully.
"Sometime there may be an increase in greenhouse gases, sometimes it may go down, there could also be heavy rainfall (potentially caused by excess heating of oceans and lands), and all this can impact the temperature," explains Hegde.
Speaking to The Quint, Earth System Scientist and retired IIT-Bombay professor Raghu Murtugudde said that a team of scientists is currently conducting a study to better understand the extent to which aerosols may be contributing to the 'South Asian warming hole'.
He goes on to say, "The research is still underway. Right now, we only know that though India is consistently cooler (compared to the global north), the season when the warming happens is when aerosols are high. Hence, the idea is that it’s unlikely that the solar dimming caused by aerosols is causing the cooling."
Balancing the Heat and Pollution Narrative: Why Clear Messaging Is Crucial
Even if it is true that aerosols resulting from air pollution is slowing warming in this region, "this is not a cause for comfort, it is a toxic illusion," says Prakash.
He adds,
"Aerosols may be suppressing surface temperatures for now, but they also harm public health by causing respiratory illnesses, altering monsoon patterns and disrupting agriculture. Crucially, if India cleans up its air and this cooling ‘mask’ lifts, the latent heat trapped by greenhouse gases could surface more intensely."
In fact, a new study published in the Environment International finds that extreme heat and air pollution together pose a greater threat to human life in India than either factor alone as extreme heat can aid particulate matter buildup in the atmosphere.
The study published in May 2025, which analysed over 3.6 million deaths across 10 Indian cities, found that the risk of death increases by 1.5 times when high temperatures are combined with poor air quality.
This is why experts stress that even if cleaning the air could lead to a slight rise in temperatures, the benefits far outweigh the risks.
"Given that far more people currently die from air pollution than from heat, I believe that even if controlling air pollution leads to some increase in warming, the overall health impact would still be positive."Anjal Prakash