An intensifying El Nino has broken a temperature record in a key zone of the Pacific in September, according to the EU's climate monitor. The Copernicus Climate Change Service reported that sea surface temperatures in the Nino3.4 region reached an all-time high of 29.70C last month. This exceeded the peak temperatures of previously strong El Nino events. The record is a sign that the weather pattern is gaining exceptional strength.
Global forecasters have been warning for months that this El Nino would likely become the strongest ever observed. The latest record has tumbled even before the episode's expected peak later this year. El Nino is a natural climate cycle that raises sea temperatures in the tropical Pacific, triggering changes in weather that can increase the risk of drought and flooding. The phenomenon typically takes place every two to seven years and lasts around nine to 12 months.
The Copernicus Climate Change Service noted that it cannot yet say that the current El Nino is the strongest ever recorded. Climate change has raised ocean temperatures, making recent El Nino events appear stronger than past ones. This complicates historical comparisons. Copernicus has adopted a new index that accounts for the warming of tropical oceans, suggesting that the current event is not yet stronger than past ones.
However, the values observed in September point to an already exceptionally strong El Nino. This is especially given that the event has not yet reached its peak. Not all forecasters use the same scale to interpret El Nino. Japan's weather agency said on Friday that El Nino conditions had reached their strongest intensity on record. Temperatures in the phenomenon's monitoring area were 4C above normal.
Record ocean temperatures were also reported in September. Global average sea surface temperatures hit a record 21.05C for September, topping the previous high of 20.92C for the same month in 2023. Overall, the world experienced its second hottest September on record, with surface air temperatures averaging 16.27C. This was 1.63C hotter than the pre-industrial average.
The United Nations declared in September that the long-term 1.5C target would be missed in a matter of years. Copernicus director Carlo Buontempo said that the world is in a new run of months above 1.5C. With a strong El Nino still intensifying, it is likely to last into 2027. Buontempo emphasized that crossing the Paris Agreement's long-term limit is only a matter of time.
Scientists stress that reducing greenhouse gas emissions from fossil fuels is crucial. This can limit the period of overshoot above 1.5C and bring temperatures back down as quickly as possible. Experts have warned that this El Nino would likely push global temperatures to a new record in 2027. The phenomenon warms surface temperatures in the central and eastern equatorial Pacific Ocean, bringing worldwide changes in winds, pressure, and rainfall patterns.
Key points
- El Nino breaks temperature record in Pacific zone
- Global average sea surface temperatures hit a record in September
- Current El Nino event likely to push global temperatures to a new record in 2027
