The countries that have contributed the least to global warming are bearing its heaviest costs. This is the stark reality at the heart of a new study on the Indian monsoon, published in Advances in Atmospheric Sciences . As India grapples with record heat and a delayed monsoon, the research paints a sobering picture: climate change is creating a deadly "dual threat" of extreme humid heat and catastrophic rainfall—while simultaneously, and unexpectedly, offering a powerful new tool to predict the monsoon up to two years in advance.
The India Meteorological Department has forecast above-normal heatwave days for June across Uttar Pradesh, Punjab, Bihar, and other states. With the monsoon delayed, experts warn of a "Great June Weather Clash"—extreme heat and high humidity combining to create dangerous "feels-like" temperatures, even as severe thunderstorms and erratic rainfall threaten other regions.
A 'Silent Killer' and a Deluge: The Dual Threat
The research, led by Prof. B. N. Goswami of Gauhati University, highlights a critical and under-recognized danger: humid heat stress. During the monsoon season, the number of days when the "feels-like" temperature exceeds 45°C is about ten times higher than the number of extremely hot dry days before the monsoon. This makes humid heat a "silent killer"—it severely limits the body's ability to cool itself and can be deadly even at seemingly manageable temperatures.
The danger is compounded. While extreme rainfall events are becoming more frequent and intense, humid heat stress peaks during the dry "break" spells of the monsoon. The result is a punishing rhythm across large parts of the country: a day or two of extreme rain, followed by days of oppressive heat. Across much of the subcontinent, residents now face either extreme rain or extreme humid heat on nearly every day of the monsoon season.
Prof. B. N. Goswami said, "We are at a critical juncture. The increasing frequency of weather extremes is challenging the very foundation of economic growth in India. Investment in research on the health impacts of prolonged humid heat—and clear public communication about these risks—is no longer optional. It is essential for survival."
The socioeconomic consequences are staggering. India now accounts for half of the global potential productivity loss from extreme heat stress—a loss driven by reduced working capacity, rising health costs, and damaged infrastructure.
An unexpected shift: the monsoon expands westward
Amid the grim outlook, the study identifies two hopeful trends. The first is a westward expansion of monsoon rainfall. While Northeast India has seen a drying trend in recent decades, this is expected to stabilize. Meanwhile, rainfall over the traditionally semi-arid Northwest India is projected to increase significantly—in some areas by as much as 150% by the end of the century. This shift could transform dry landscapes, boost food production, and improve water availability in regions that have long struggled with scarcity.
The researchers caution, however, that this opportunity comes with challenges. Increased rainfall in the northwest may require farmers to transition from traditional millet cultivation to wheat and rice, while the rising frequency of extreme downpours could cause soil erosion and flooding in areas unprepared for such changes.
A prediction breakthrough: looking two years ahead
The second and perhaps most transformative finding concerns monsoon prediction. For decades, scientists feared that climate change was making the monsoon less predictable. The study turns this assumption on its head. By using a new "Global ENSO" predictor based on deep ocean temperatures—rather than just surface temperatures—the researchers found that the Indian monsoon remains highly predictable, even under intense global warming. In fact, monsoon rainfall can be forecast with strong accuracy up to 18 months in advance.
Devabrat Sharma, a co-author from the Indian Institute of Technology Madras, explained:
"For decades, we relied on sea surface temperatures to predict the monsoon, but that approach was noisy and unreliable. Our work shows that deep ocean temperatures hold a far clearer signal, allowing us to look years ahead rather than just months. This changes the game for how we prepare for climate extremes."
This breakthrough could revolutionize long-term planning for agriculture, water storage, and disaster response—giving farmers, policymakers, and communities the lead time needed to prepare for both droughts and floods.
A call to action—and a question of justice
The authors call for rapid global action to curb emissions, while simultaneously building local resilience through better prediction, stronger infrastructure, and adaptive farming practices. But they also underscore a fundamental injustice: the nations suffering most from climate change have done the least to cause it. The tools to prepare for the future now exist. The question is whether the world—and especially the nations most responsible for the crisis—will act.
The study is included in a WCRP Monsoon Panel Special Issue on Global and Regional Monsoons .
