Scientists are warning that the El Niño effect is set to see several areas of the globe likely to experience record-breaking average surface air temperatures in the year up to June 2024.

The  team of scientists cite areas including the Bay of Bengal, the Philippines, and the Caribbean Sea will see record temperatures as a result of the ongoing El Niño phenomenon. The modelling results, also suggest that there is an estimated 90 percent chance of record-breaking global mean surface temperatures occurring over the same period under a moderate or strong El Niño scenario.

The El Niño-Southern Oscillation, centred in the tropical Pacific, is a key driver of climate variability around the world. Both its warm phase, El Niño, and its colder phase, La Niña, influence weather conditions, with the heat released to the atmosphere from the western Pacific Ocean during an El Niño leading to an accelerated rise in annual global mean surface temperatures (GMST). A slight increase in GMST has been strongly linked to significant increases in surface air temperatures during extreme regional heating events.

Congwen Zhu and colleagues modelled the effects of the 2023 – 24 El Niño on the regional variation in average surface air temperatures from the 1951 – 1980 mean between July 2023 and June 2024. They used this period to ensure that the typical peak of an El Niño event, between November and January, was always included.

They found that under a moderate El Niño scenario, the Bay of Bengal and the Philippines were predicted to experience record-breaking average surface air temperatures over the period. Under a strong El Niño, the Caribbean Sea, South China Sea, and areas of the Amazon and Alaska were also predicted to experience record-breaking average surface air temperatures. The authors also modelled the effects of El Niño on GMST over the same period and found that under a moderate or stronger El Niño, there was a 90% chance that GMST would break the historical record. In the moderate scenario, the authors estimated the 2023 – 24 GMST as being 1.03 – 1.10 °C above the benchmark 1951 – 1980 mean, whilst for the strong scenario, they estimated GMST as 1.06 – 1.20 °C above that mean.

They warn that record-breaking average temperatures will likely challenge regions’ current capability to cope with the consequences of excess heat.

They added that high surface air temperatures can lead to a significant increase in the likelihood of extreme climate events — including wildfires, tropical cyclones, and heatwaves — particularly in oceanic and coastal areas where the higher heat capacity of the ocean leads to climate conditions persisting for extended periods of time.

The study which came from a team of Researchers from Massachusetts General Hospital and Brigham and Women’s Hospital, added there is growing  evidence vulnerable populations such as the elderly are increasingly threatened by climate events. They examined how weather disasters between 2011 and 2016 influenced healthcare delivery and mortality among Medicare beneficiaries in affected US counties, finding that one week after major weather events, emergency department (ED) use and mortality remained elevated by 1.22% and 1.4%, respectively, from pre-disaster levels. Importantly, this study also found that deaths remained elevated for as much as six weeks.

Counties with the greatest economic losses were found to have two to four times higher mortality rates – and higher ED usage – compared to all affected counties, highlighting how infrastructure destruction, such as power outages and transportation challenges, may compound both economic and healthcare tolls.

“Taken together, these findings suggest that the biggest weather disasters have broad and long-lasting impacts on health emergencies and deaths among those who have Medicare,” said lead author Renee Salas, of the Department of Emergency Medicine at Massachusetts General Hospital. “Tracking these outcomes is important to better protect patients and communities – and to strengthen our health systems.”