An intensifying El Nino weather pattern set a new temperature record in a key region of the Pacific Ocean in September, according to the European Union’s climate monitoring agency. The Copernicus Climate Change Service reported that sea surface temperatures in the El Nino tracking area known as Nino3.4 reached 29.7 degrees Celsius last month, surpassing the peaks recorded during previous strong events in 1982-83, 1997-98, and 2015-16. This development signals the exceptional strength of the current El Nino episode, which has yet to reach its expected peak later this year.
El Nino is a natural climate cycle characterized by warming sea surface temperatures in the central and eastern tropical Pacific. It influences global weather patterns by altering winds, rainfall, and atmospheric pressure. The phenomenon often increases the risk of droughts and flooding in various regions worldwide and tends to intensify the impacts of human-induced global warming.
Despite the recorded temperature milestone, Copernicus noted it cannot definitively claim that the ongoing El Nino is the strongest ever observed. The agency employs a new measurement index that accounts for the general warming of tropical oceans due to climate change. This adjustment complicates straightforward comparisons to previous events but still confirms the current episode is exceptionally intense given it has not yet peaked.
Japan’s Meteorological Agency also reported last week that El Nino conditions had reached their strongest recorded intensity, with sea surface temperatures in the monitoring zone measuring about 4 degrees Celsius above historical norms.
The broader climate context is notable. Copernicus data shows that global average sea surface temperatures hit a record 21.05 degrees Celsius in September, surpassing the previous high for the month set earlier this year. Additionally, Earth experienced its second warmest September on record, with surface air temperatures averaging 16.27 degrees Celsius—1.63 degrees above pre-industrial levels defined as 1850-1900.
These temperature increases highlight the challenges facing worldwide climate goals. The 2015 Paris Agreement set targets to limit global warming to well below 2 degrees Celsius, and preferably to 1.5 degrees, compared to pre-industrial times. However, the United Nations recently warned that the 1.5-degree threshold is likely to be exceeded within a few years.
Carlo Buontempo, director of Copernicus, stated that sustained temperatures above 1.5 degrees are expected, driven by the intensifying El Nino. He emphasized that although exceeding this limit appears imminent, the extent and duration of the overshoot depend on collective efforts to reduce greenhouse gas emissions.
Scientists stress that rapid cuts in emissions from fossil fuels are essential to minimize the period over which global temperatures remain above 1.5 degrees Celsius and to return to safer climate conditions as swiftly as possible. Experts also predict that the current El Nino could drive global temperatures to a new high around 2027.
El Nino events occur irregularly, typically every two to seven years, and usually last between nine and twelve months. The current episode’s significant strength and timing underline its potential to influence global climate patterns and exacerbate ongoing warming trends in the near term.