India's worst phase of summer is yet to come, with air pollution to be the cause, according to a report.

The worst phase of heat resulting from the climate crisis in India is yet to come. According to new research, between 1980–90 and 2015–24, India’s landmass warmed by only 0.88°C, whereas the global average increase stood at 1.4°C. One of the primary reasons behind this disparity is air pollution.

This research paper, titled “A Critical Perspective on Extreme Heat in India,” was released by Harvard University’s Salata Institute for Climate and Sustainability. It states that the processes currently suppressing heat in India will not persist indefinitely. Therefore, understanding this “warming gap” is crucial when formulating adaptation strategies.

The Mystery of Lower Heat in North India

Compared to the national average, North India is experiencing less warming in its winter daytime temperatures. In some regions, a cooling trend is even becoming apparent during the month of January. During the months of October, November, and December as well, the rise in temperatures in North India remains lower than the national average.

The primary reasons for this are the heavy air pollution and intensive irrigation prevalent in the region. North India serves as the country’s granary. Aerosols keep the surface cool during the day by scattering or absorbing sunlight. Additionally, evapotranspiration resulting from irrigation also generates a cooling effect.

The Dual Impact of Clean Air Policies

Initiatives such as the National Clean Air Programme and various state-level measures could lead to a reduction in aerosol levels—that is, air pollution. While this would undoubtedly improve public health, it would also lift the partial lid currently suppressing greenhouse-induced heat. Consequently, North India could witness a moderate rise in its winter daytime temperatures.

The research paper warns that heat action plans, agricultural forecasts, labor protection protocols, and financial instruments—all currently designed based on historical averages—may underestimate the actual heat conditions of the future. The warming trend that has appeared relatively mild thus far may not remain so going forward.

Increased Risk for Millions of Indians Working in the Heat

Approximately three-quarters of India’s workforce—totaling nearly 380 million people—are engaged in sectors where work is performed under conditions of heat. These sectors include agriculture, construction, and informal businesses, which collectively account for nearly half of the country’s GDP. According to Sachit Balsari, an Associate Professor at Harvard, this risk is set to intensify further in the near future.

By 2030, as many as 200 million people in the country could face conditions of deadly heat. Heat stress is projected to impact tens of millions of jobs worldwide. The capacity for adaptation is uneven; only 8% of households in the country possess air conditioners. The remainder of the population is coping with the heat using limited or ineffective methods.

Rainfall in India Could Increase by Over 20%

According to certain climate models, under a worst-case scenario, India’s annual rainfall could increase by more than 20% by the end of the century, while some models project an increase exceeding 60%. In either scenario, farmers will require substantial adaptation measures.

Reducing uncertainty within these models constitutes a critical research priority. As the climate warms, predictions also indicate an increase in year-to-year fluctuations in rainfall. Consequently, accurate long-term forecasts are essential for farmers.

Extremely high temperatures are projected to rise across all climate scenarios. Furthermore, if trends in relative humidity in India are being influenced by anthropogenic carbon emissions, this presents a cause for concern.