El Niño conditions have developed in the tropical Pacific for the first time in seven years, setting the stage for a likely surge in global temperatures and disruptive weather and climate patterns.
A new Update from the World Meteorological Organisation (WMO) forecasts that there is a 90% probability of the El Niño event continuing during the second half of 2023.
“The onset of El Niño will greatly increase the likelihood of breaking temperature records and triggering more extreme heat in many parts of the world and in the ocean,” said WMO Secretary-General Prof. Petteri Taalas in a press release.
“The declaration of an El Niño by WMO is the signal to governments around the world to mobilise preparations to limit the impacts on our health, our ecosystems and our economies,” he said. “Early warnings and anticipatory action of extreme weather events associated with this major climate phenomenon are vital to save lives and livelihoods.”
El Niño occurs on average every two to seven years with episodes typically lasting nine to twelve months on average. It is a naturally occurring climate pattern associated with warming of the ocean surface temperatures in the central and eastern tropical Pacific Ocean.
The WMO report in May, led by the UK’s Met Office with partners around the world, also said there is a 66% likelihood that the annual average near-surface global temperature between 2023 and 2027 will temporarily be more than 1.5°C above pre-industrial levels for at least one year.
“This is not to say that in the next five years we would exceed the 1.5°C level specified in the Paris Agreement because that agreement refers to long-term warming over many years. However, it is yet another wake up call, or an early warning, that we are not yet going in the right direction to limit the warming to within the targets set in Paris in 2015 designed to substantially reduce the impacts of climate change” said WMO Director of Climate Services Prof. Chris Hewitt.
According to WMO’s State of the Global Climate reports, 2016 is the warmest year on record because of the “double whammy” of a very powerful El Niño event and human-induced warming from greenhouse gases. The effect on global temperatures usually plays out in the year after its development and so will likely be most apparent in 2024.
Typical impacts of El Niño
El Niño events are typically associated with increased rainfall in parts of southern South America, the southern United States, the Horn of Africa and central Asia.
In contrast, El Niño can also cause severe droughts over Australia, Indonesia, parts of southern Asia, Central America, northern South America and southern Africa.
During the Boreal summer, El Niño’s warm water can fuel hurricanes in the central/eastern Pacific Ocean, while it could hinder hurricane formation in the Atlantic Basin.
Generally, El Niño has the opposite effect of the recent La Niña, which ended earlier in 2023.
Current situation and outlook.
The collective evidence from both oceanic and atmospheric observations strongly points towards the presence of El Niño conditions in the Pacific. However, some uncertainty remains because of only weak ocean-atmosphere coupling, which is crucial for the amplification and sustenance of El Niño.
The WMO anticipates that it will take approximately another month or so to witness a fully established coupling in the tropical Pacific.