The El Niño weather pattern is likely to develop later this year and could contribute to rising global temperatures, according to the World Meteorological Organization (WMO).
During El Niño, winds blowing west along the equator slow down, and warm water is pushed east, creating warmer surface ocean temperatures.
The WMO said that after three years of the La Nina weather pattern in the Pacific Ocean, which often lowers global temperatures slightly, there was a 60% chance that will change to El Niño, its warmer counterpart, in May-July this year.
That probability will increase to 70-80% between July and September, according to the WMO.
“We just had the eight warmest years on record, even though we had a cooling La Niña for the past three years and this acted as a temporary brake on global temperature increase. The development of an El Niño will most likely lead to a new spike in global heating and increase the chance of breaking temperature records,” said WMO Secretary-General professor Petteri Taalas.
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.
“The world should prepare for the development of El Niño, which is often associated with increased heat, drought or rainfall in different parts of the world. It might bring respite from the drought in the Horn of Africa and other La Niña- related impacts but could also trigger more extreme weather and climate events. This highlights the need for the UN Early Warnings for All initiative to keep people safe,” said professor Taalas.
No two El Niño events are the same and the effects depend partly on the time of year. WMO and National Meteorological Hydrological Services will therefore be closely monitoring developments.
However, the WMO was hedging its bets regarding the extent of the weather phenomenon’s effect on temperatures. Wilfran Moufouma Okia, head of the WMO regional climate prediction services division, said there was no current estimate of how much El Niño would push temperatures up.
“El Nino will fuel the temperature globally,” he said. “We feel the effect of El N Niño temperatures globally with a slight delay.”