Will temperatures drop as El Niño comes to an end?
Over the last 10 months El Niño has boosted global temperatures to record breaking highs, but this climate pattern now looks to be weakening.
We spoke to climate scientist Dr Kieran Hunt at the National Centre for Atmospheric Science about the transition from El Niño to ENSO-neutral conditions, what this means for global temperatures, and what will happen next.
What is El Niño?
“El Niño is a climate pattern that is defined as anomalous warming of surface and sub-surface waters in the eastern and central tropical Pacific Ocean. More specifically, El Niño is the name given to the warm phase of a larger phenomenon called El Niño-Southern Oscillation also known as ENSO,” sets out Dr Kieran Hunt, a climate scientist at the National Centre for Atmospheric Science and University of Reading.
El Niño and global temperatures
El Niño acts as a giant heat source in the tropics, in turn affecting atmospheric circulation, which then influences global climate and weather patterns worldwide. Stronger El Niño events can lead to increased global temperatures.
2023 saw a string of monthly global temperature records being broken, which continued into early 2024. March 2024 marked the tenth month in a row where a new global temperature record was set.
Alongside human-induced climate change, El Niño had a big impact on the soaring temperatures. However as El Niño comes to an end, which is likely by April–June 2024, global temperatures may begin to drop.
What happens after El Niño?
Dr Kieran Hunt explains: “When an El Niño event ends it is typically followed in the summer by neutral conditions. In the following winter, it is then common to see a La Niña event, which is the opposite climate pattern to El Niño. However, this is not always the case as the two events do not necessarily alternate.”
La Niña events can last between 1–3 years and typically have the opposite effect to El Niño – the cooler phase of ENSO.
The onset of La Niña could lower global temperatures. Between 2020 and 2022, the world experienced three consecutiveLa Niñas, which helped keep global temperatures lower.
It is estimated that there is a 60% chance La Niña will develop by late June – August 2024; however exactly if or when a La Niña event develops is difficult to predict this far in advance.