Heatwaves and cyclones: India’s tryst with climate change

Climate scientist Roxy Mathew Koll posted a very interesting satellite image of the Indian subcontinent on social media. In it, one can see three things: Cyclone Remal poised to make landfall at the Sunderbans delta, the monsoon nearing the Kerala coast, and scattered red dots across north and central India (a dense cluster of which lay over Delhi, Punjab and Haryana) marking the regions suffering from an intense heatwave.

This image is a fascinating portrait of the way climate change is already affecting India. It has long been established that India is one of the few countries that will face every possible impact of global warming—be it deadly heatwaves, loss of glaciers, sea level rise, unpredictable monsoon or ever-intense cyclones. What’s more, given the country’s geographical location, it would all happen together.

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What the past week has shown, if indeed it still needed to be shown, is that this isn’t just a prognosis of a possible future, but one that is already happening. On Wednesday, New Delhi recorded its highest ever maximum temperature, that of 52.3 degrees Celsius, a whopping 10-11 degrees above normal. In fact, so high was this that the Indian Meteorological Department (IMD) is currently checking if the station that recorded this had malfunctioned. But this was not an isolated high. Through the preceding week, the maximum temperature has been in the high 40s, many degrees above normal. A potent mix of climate change and unplanned urbanization has turned the national capital into a frying pan.

In a statement, Vishwas Chitale, senior programme lead at policy body Council on Energy, Environment and Water (CEEW), said that the severe heatwave in Delhi bears out recent findings that Indian cities are warming at nearly twice the rate as the rest of the country due to the potent mix of climate change and urbanization. “The impacts we are witnessing are multifaceted, which includes water scarcity and record-breaking power demand. To adapt to these conditions, it is imperative that our heat action plans shift from a response-centric to a preparedness-centric approach, mapping granular-level heat risks to help administrators prioritize health interventions,” he said.

This is evidently not just a question of Delhi experiencing a heatwave. The surrounding region, across states, has been burning as well, with the IMD issuing a ‘red alert’ warning of severe heatwave conditions on 28 May for two days across six states: Rajasthan, Punjab, Haryana, Delhi, Western Uttar Pradesh and Madhya Pradesh.

As a study published by the Delhi-based think tank Centre for Science and Environment (CSE) —titled Decoding The Urban Heat Stress Among Indian Cities—a few days ago shows, cities are becoming increasingly vulnerable to rising heat stress, especially deadly humid heat. The fact that cities are registering higher night temperatures adds to the deadliness.

At the same time as these heatwaves, a major cyclone, Remal, made landfall in the Bengal coast on 26 May, causing extreme damage, and claimed a few lives. In fact, even as the cyclone lost its strength after landfall and became a major storm, it remained intense enough to cause heavy rains leading to major landslides in Northeast states like Manipur. For a depression to develop into a severe cyclone in so short a time, the reason was abnormally high sea surface temperatures (SSTs) in the Bay of Bengal, another result of climate change.

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In the weeks leading up to the formation of the cyclone, Koll had said in another social media post on 19 May, Bay of Bengal SST had been persistently 2-3 degree Celsius above normal. “Persistently high sea surface temperatures provide constant supply of heat and moisture, essential for cyclone formation,” he wrote.

Last month, Koll—who is a scientist at Centre for Climate Change Research at the Indian Institute of Tropical Meteorology in Pune, focusing on the Indian Ocean region—along with a group of international scientists, published an important paper in the journal Science Direct, called Future Projections For The Tropical Indian Ocean that showed that the Indian Ocean is warming at an alarming pace, between 1.7-3.8 degrees Celsius per century.

Speaking to Lounge about the implications of this finding, Koll says this would mean that the Indian Ocean would be in the grips of perpetual marine heatwaves (like the one that caused the formation of Cyclone Remal). He says that in such conditions coral reefs and their biodiversity could disappear, since coralshave a very limited range of tolerance, in terms of ocean temperatures. “The other impact would be in the form of extreme weather events (like cyclones) which reach land, and cyclones intensifying rapidly in both the Bay of Bengal and the Arabian Sea. The variability in the monsoon could be much more intense: You would get extreme rains,” he says.

He also says that rising Indian Ocean heat translates into the Indo-Pacific turning into a “frying pan”. “The Indo-Pacific is one of the most vulnerable regions in terms of extreme events in recent times, whether it is rains or tropical storms and heatwaves and other impacts. We need urgent action in terms of emissions mitigation and local adaptation, and that is not happening.”