Heatwaves & Cool Heads

This article originally appeared in The Times of India

We shouldn’t panic about summer extremes, because there are well-understood solutions. The trick is to implement them smartly

Dear Sir,
I write to you from Lucknow, hoping you could answer some of my questions.
1.  Are we inevitably headed towards an unlivable India due to heatwaves?
2.  Do you believe Stratospheric Aerosol Injection (SAI) is imminent? Will India be forced to use this technology?
3.  What can we do to adapt to increasing heat?
4.  Are you optimistic about the future?

(Name withheld)

As I was gearing up to write my monthly column, I received the above email from a young man who is clearly worried about the future. Given that his concerns are shared by millions of young people in our country, I have decided to use this platform to address them. I believe it is critical to empower the next generation with the right knowledge and perspective instead of debilitating them with fear.

Since the publication of Kim Stanley Robinson’s fictional novel The Ministry for the Future, some climate scientists have painted a doomsday scenario about deadly heatwaves in the Indian sub-continent. The book features an outlandish storyline in which a small Indian town is hit by an unsurvivable wet-bulb temperature heatwave, resulting in the death of all its inhabitants within a week. The Indian government responds by using SAI, which involves spraying sulphur dioxide into the atmosphere to mimic the cooling effect of a volcanic
eruption. The plot also includes an eco-terrorist network, the “Children of Kali”, which uses drones to crash passenger jets to protest against continuing carbon emissions.

Now think about the absurdity of the plot. It is inconceivable that any government would allow its citizens to die in high heat and humidity for a week without providing assistance or transferring them to a safer location. Similarly, SAI would not immediately cool the area or
save lives. It would take months before the planet starts cooling due to sulphur spray. Thus, there is no logical reason for the Indian government to spray sulphur dioxide into the atmosphere just after the deadly heatwave.

Despite these improbabilities, Robinson’s book has acquired cult status, partly due to endorsement from the likes of Barak Obama and Bill Gates, leading to the distortion in the views of impressionable minds. So my first answer to the young man is that deadly heatwaves will affect us badly, but they will not make India unlivable. We have a range of adaptation technologies and measures to deal with them. And we do not need technologies like SAI, with its enormous uncertainty and unintended consequences, to manage extreme heat. Let me explain.

It is a fact that heatwaves have increased every decade since the 1980s, and they now engulf most of the country. The worrying part is that temperature and humidity are rising together, leading to high wet-bulb temperatures. For example, the recent deaths in Kharghar in
Maharashtra were due to a combination of heat and humidity. The temperature was only about 36-37°C, but the humidity was 50-60%, taking the wet-bulb temperature near 30°C, which is dangerous for manual labour and the vulnerable population outside.

Therefore, there is no doubt that we have entered an age of hot extremes when the global temperature has increased by only 1.2°C from the pre-industrial era. At 1.5°C warming, there will be more severe heatwaves. At 2°C, “deadly” heatwaves would frequently cross 35°C
wet-bulb temperatures, which is the limit of human survivability. In addition, the number of days workers will have difficulty working outside will increase to 200-250 per year, which our economy cannot afford. So what do we do about this? Should we allow temperatures to keep increasing and then spray sulphur to cool the planet, or should we try to limit warming and adapt to heatwaves?

The answer is obvious: reducing carbon emissions is the cheapest and the best option to limit warming and deadly heatwaves. This we can do by deploying existing technologies – solar and wind energy, energy-efficient appliances, green buildings, electric vehicles, reducing
wasteful consumption – that will also support green growth and jobs. The good news is that these technologies are picking up. For example, in 2022, 40% of global electricity was produced from non-fossil sources (25% in India). If this trend continues, we can decarbonize
the global electricity supply by 2040-50, limiting warming to below 2°C.

Similarly, we can re-design our cities and buildings to adapt to heatwaves. This entails incorporating more open spaces, green areas, and water bodies into urban landscapes. Additionally, our buildings must be energy-efficient, with well-insulated walls and roofs and effective shading and ventilation systems to maintain a cool interior. But still, we will have to provide some cooling solutions to all buildings considering the high heat intensity. However, the current cooling technology, vapour-compression air conditioners, is part of the problem
due to its high energy consumption, harmful refrigerants, and contribution to heat islands. Therefore, we must replace outdated technologies with a new generation of affordable and green cooling solutions.

Finally, we need a new heat code based on the wet bulb temperature to avoid incidents like Kharghar. Many regions now experience wet-bulb temperatures exceeding 30°C during certain parts of the year, and our guidelines based on dry-bulb temperature do not capture
this.

I am optimistic about the future because every solution I have mentioned here is achievable. Moreover, the decarbonization trajectory globally and in India is moving in the right direction. Furthermore, I see the younger generation being more mindful and proactive about
addressing the climate crisis than my generation ever was. So my advice to the young man is: be more optimistic as yours will be the first generation that will play a heroic role in saving the planet.