The record global heat driven by this year’s powerful “super El Niño” could cause nearly 451,000 deaths worldwide between June 2026 and February 2027, compared with an average year.
According to a report titled “451,000 at Risk: Where Action Can Save Lives During the Super El Nino”, published on Wednesday by global research collaboration Climate Impact Lab (CIL), the frequency of extremely hot days is projected to increase by 44 per cent compared with normal years.
The researchers based their projections on the relationship between temperature and excess mortality across 24,378 regions. They also considered local climate and vulnerability alongside temperature forecasts compared with the 1996–2025 average. The report’s methodology is scheduled to be published in a peer-reviewed journal, reports Al Jazeera.
Researchers described this year’s El Niño as a “postcard from the future”, warning that it signals temperatures that could become the new normal within a few decades. They urged authorities to immediately deploy emergency measures in high-priority regions to reduce heat-related deaths in the coming months.
CIL’s Adaptation Inventory recommends heat warnings, additional medical staff during peak heat periods, cooling centres and workplace protections for outdoor workers to help vulnerable populations.
Michael Greenstone, an economist at the University of Chicago and cofounder of CIL, said the report allows decision-makers to identify where emergency measures could save tens of thousands of lives in the coming months.
How super El Niño develops
El Niño occurs when the central and eastern equatorial Pacific Ocean becomes at least 0.5 degrees Celsius (0.9 degrees Fahrenheit) warmer than average. It is part of a natural climate cycle that alternates with the cooler La Niña phase.
The phenomenon is classified as a “super El Niño” when ocean surface temperatures reach or exceed 2C (3.6F) for several months. The current El Niño reached 2.7C last month, with forecasts suggesting it could rise to 4C when it peaks between November and December.
Akshay Deoras, senior research scientist at the University of Reading’s National Centre for Atmospheric Science and Department of Meteorology, said El Niño’s development depends heavily on atmospheric and oceanic conditions.
He said unusually strong spring winds from Indonesia transported a large volume of warm water towards the eastern equatorial Pacific Ocean, triggering this year’s super El Niño.
Global weather disruptions
The full extent of the resulting weather disruptions is still being assessed, but Adam Scaife, head of long-range forecasting at the United Kingdom’s Met Office, said the expected effects are already being seen worldwide.
The Met Office said El Niño significantly changes global rainfall patterns, putting parts of Central and northern South America, the western Pacific, areas affected by the Indian summer monsoon and Southern Africa at greater risk of reduced rainfall and drought.
El Niño also suppresses tropical cyclone activity in the Atlantic, with the Met Office recording no hurricanes so far this year.
Such widespread rainfall disruptions pose serious risks to global food supplies by damaging agriculture and altering natural growing and harvesting seasons. Deoras said El Niño releases a large amount of heat into the atmosphere, increasing the frequency, intensity and severity of extreme weather events and potentially causing high casualties worldwide in the coming months.
Climate change worsens impacts
Friederike Otto, professor of climate science at Imperial College London, warned that climate change driven by fossil fuel emissions is worsening El Niño’s effects around the world.
Otto said El Niño is a recurring natural phenomenon, but heat generated by fossil fuel emissions will continue to push global temperatures higher unless rapid global action is taken to move away from fossil fuels.
Global South faces highest mortality burden
The CIL report warns that countries in the Global South will bear the heaviest mortality burden.
Nigeria is projected to record the highest number of excess heat-related deaths at 31,400, followed by Indonesia with 19,300 and Sudan with 17,600.
Across Africa’s Sahel region, which includes Niger, Chad, Nigeria and Sudan, excess heat is expected to claim 66,800 lives. The Philippines, Vietnam, Thailand and Cambodia are projected to record a combined 19,400 excess deaths.
Researchers warned that the death toll could rise if El Niño continues into next year, leaving Northern Hemisphere countries such as India and Pakistan particularly vulnerable during their summer months.
Tom Burke, cofounder and director of climate change think tank E3G, said poorer countries in the Global South lack the complex institutional infrastructure, including health systems and fire departments, available in the Global North to respond to such extreme stresses.
Burke described the report’s figure of nearly half a million deaths as conservative, saying it does not include deaths from El Niño-related fires, floods and food price inflation compounded by conflicts such as the US-Israel war on Iran.
However, Deoras described the projections as subjective and questioned some of the regional figures, including the projection of more than 15,000 excess deaths in India by February 2027, given that deadly dry heatwaves do not coincide with India’s non-summer months.
He nevertheless said widespread deaths, property damage, infrastructure disruption and economic losses remain highly probable over the next 12 months.
