The United Nations on July 4 declared the onset of the El Nino weather phenomenon. The World Meteorological Organization (WMO) marked the first occurrence of El Niño in the tropical Pacific in seven years and sets the stage for potentially elevated global temperatures and disruptive weather patterns.
The World Meteorological Organization (WMO) has released an update forecasting a 90% probability of the El Niño event continuing throughout the second half of 2023. It is expected to be of at least moderate strength. The WMO Update combines forecasts and expert guidance from around the world.
WMO Secretary-General Prof.Petteri Taalas warns, “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.”
“The declaration of an El Niño by WMO is the signal to governments around the world to mobilize 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.”
OCCURRENCE
El Niño occurs every two to seven years, with episodes typically lasting nine to twelve months. It is a natural climate pattern associated with the warming of ocean surface temperatures in the central and eastern tropical Pacific Ocean. However, El Niño now occurs within the context of a climate influenced by human activities.
Anticipating the El Niño event, a WMO report released in May predicted a 98% likelihood that at least one of the next five years, as well as the entire five-year period, will be the warmest on record. It said that this would surpass the record set in 2016 during an exceptionally strong El Niño. The report also noted a 66% likelihood that the annual average near-surface global temperature between 2023 and 2027 will temporarily exceed 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.
THE TEMPERATURE
WMO’s State of the Global Climate reports have revealed that 2016 was the warmest year on record, largely due to the combination of a powerful El Niño event and human-induced greenhouse gas warming. The impact on global temperatures typically becomes apparent in the year following the development of El Niño, making it likely that the effects will be most noticeable in 2024.
The average global temperature in 2022 was about 1.15 °C above the 1850-1900 average because of the cooling triple-dip La Niña.
WMO’s State of the Global Climate reports have revealed that 2016 was the warmest year on record, largely due to the combination of a powerful El Niño event and human-induced greenhouse gas warming. The impact on global temperatures typically becomes apparent in the year following the development of El Niño, making it likely that the effects will be most noticeable in 2024.
CURRENT SITUATION AND OUTLOOK
Currently, sea surface temperature anomalies in the central-eastern equatorial Pacific have significantly increased, indicating the presence of El Niño conditions. However, some uncertainty remains due to weak ocean-atmosphere coupling, which is crucial for the amplification and sustenance of El Niño. It is expected to take about another month to observe fully established coupling in the tropical Pacific.
GLOBAL SEASONAL CLIMATE UPDATE
El Niño and La Niña are major – but not the only – drivers of the Earth’s climate system.
In addition to the long-established ENSO Update, WMO now also issues regular Global Seasonal Climate Updates (GSCU). It incorporate influences of the other major climate drivers such as the North Atlantic Oscillation, the Arctic Oscillation and the Indian Ocean Dipole.
The updates provide forecasts on temperature and rainfall patterns to support governments, decision-makers, and stakeholders in climate-sensitive sectors.
National Meteorological and Hydrological Services (NMHSs) will closely monitor the evolution of El Niño conditions and the associated impacts on temperature and precipitation at national and local level. WMO will provide updated outlooks during the coming months as needed.
