CHENNAI: The heat is on though we are yet to enter the actual throes of summer, and if experts are to be believed, Tamil Nadu may record extreme heat and erratic rainfall this year due to the likelihood of a strong El Nino, coupled with the relentlessly rising global temperatures.
The global climate projections by climate scientist Zeke Hausfather of the University of California point to an increase in the expected global temperature anomaly for 2026 to around 1.51°C above pre-industrial levels, driven by a strengthening El Nino-Southern Oscillation (ENSO).
While 2026 may not surpass the heat of 2024, the worst year in recorded history, it is almost certain to rank among the warmest years ever recorded. More significantly, due to the delayed response between ocean warming and surface temperatures, 2027 is now widely expected to become the hottest year on record.
According to climate scientists, El Nino weakens the monsoon, delays seasonal rains, and increases temperatures, leading to heatwaves, water shortages, and drought-like conditions in many regions. If the early predictions of a strong El Nino come true, Tamil Nadu will face extreme heat and erratic rainfall, which would add pressure on water and agriculture systems.
M Rajeevan, former secretary of the Ministry of Earth Sciences, noted that there was a high probability that an El Nino event will develop and added that seasonal forecasts suggest that it could evolve into a strong one.
“…there is reason for cautious concern regarding the potential development of a strong El Nino event during the coming monsoon season. Given the current uncertainties, clearer signals are likely to emerge by May 2026,” he said, urging the authorities to closely monitor the situation and begin considering strategic response measures.
Tamil Nadu is particularly vulnerable to extreme heat events, which are becoming more frequent and intense. Urban centres such as Chennai are already experiencing prolonged heatwaves, which may worsen.
As worrying as it is, that is not all. El Nino events are historically associated with disruptions in India's monsoon cycles, including the Northeast Monsoon that Tamil Nadu mainly depends on for its annual rainfall. A strong El Nino could weaken or delay these rains, leading to prolonged dry spells and water shortages.
This in turn could affect water security, as the reservoirs supplying drinking water to Chennai and its neighbourhood would come under pressure in the event of a deficit monsoon.
In the Cauvery Delta, the impact would be visible in the form of reduced crop yields, effect on planting cycles, while increased dependence on groundwater would deplete the already stressed aquifers.
Speaking to DT Next, climate activist Veltri Selvan associated with the NGO, Poovulagin Nanbargal, noted how scientists were predicting a "super El Nino" this year. Citing recent findings from the World Meteorological Organisation (WMO), he pointed out that the past three years were the warmest on record globally. "Despite the influence of La Nina conditions, the heat was still unbearable last year. This shows how rapidly temperatures are rising," he said.
He stressed the urgent need for greater public awareness, particularly among unorganised sector workers who are the most vulnerable to extreme heat, and the healthcare system to be better equipped to handle heat-related illnesses.
El Nino is a climate phenomenon marked by unusual warming of surface waters in the central and eastern Pacific Ocean, which disrupts global weather patterns. In India, it often weakens monsoon rainfall, delays seasonal rains, and increases temperatures, leading to heatwaves, water shortages, and drought like conditions in many regions.