US scientists have confirmed the onset of El Niño, a natural weather phenomenon occurring in the Pacific Ocean. Experts predict that this event will likely make 2024 the hottest year globally, raising concerns about surpassing the critical 1.5C warming threshold. The effects of El Niño are also expected to impact weather patterns worldwide, potentially causing drought in Australia, increased rainfall in the southern US, and a weakened monsoon in India.
The event is projected to last until the following spring, after which its impacts will diminish. Researchers have been increasingly confident in the emergence of El Niño for several months, with expectations of it peaking in intensity by the end of this year. Adam Scaife, the head of long-range predictions at the UK Met Office, stated that a new record for global temperature in 2024 is highly plausible if El Niño turns out to be significant.
El Niño, formally known as the El Niño Southern Oscillation (ENSO), is the most influential climate fluctuation on Earth. It has three phases: hot, cold, and neutral. The hot phase, or El Niño, occurs every two to seven years and involves warm waters surfacing off the coast of South America, releasing substantial heat into the atmosphere.
Record warm years, such as 2016, the hottest year on record, often follow powerful El Niño events. Different weather agencies employ various criteria to determine the onset of the hot phase. According to the US National Ocean and Atmospheric Administration (NOAA), El Niño conditions were met in May, although the signal was relatively weak. NOAA scientists expect the conditions to intensify further.
Researchers estimate an 84% chance of this El Niño event reaching moderate strength by the end of the year. There is also a one in four chance of it surpassing 2C, potentially qualifying as a “super El Niño.” The impacts of El Niño are likely to manifest several months after its onset and will be felt globally. These effects include drier conditions in Australia and parts of Asia, potential weakening of India’s monsoon, and increased rainfall in southern US states. Historically, El Niño has exacerbated drought conditions in Africa.
The potential human and economic costs of this forthcoming weather event are significant. The strong El Niño in 1997-98 resulted in over $5 trillion in damages and approximately 23,000 deaths from storms and floods. Additionally, there is a strong likelihood that this year’s El Niño could push 2024 beyond 2016 as the hottest year on record.
Global temperatures are currently approximately 1.1C above the average from 1850-1900. However, El Niño could add up to 0.2C to that figure, bringing the world closer to surpassing the symbolic 1.5C guardrail set by the Paris climate agreement. Scientists recently suggested that temporarily exceeding this limit is more likely than not in the coming years. Michelle L’Heureux, a scientist with NOAA, emphasizes that El Niño acts as an accelerant to global warming, raising concerns about future temperature thresholds.
