Key Points
- Oceans are absorbing around 90% of excess heat generated by human activity.
- April ranked as the third hottest month globally on record, according to Copernicus data.
- Marine heatwaves between the tropical Pacific and the United States have already broken records.
- Arctic sea ice remained near record lows during April.
- Scientists warn Europe could face a hotter, drier summer, increasing risks of drought and wildfires.
PARIS: Ocean temperatures are edging dangerously close to record highs and could surpass previous levels within days as global climate conditions shift towards a potentially strong El Niño event, the European Union’s climate monitoring service warned on Friday.
The Copernicus Climate Change Service, overseen by the European Centre for Medium-Range Weather Forecasts (ECMWF), reported that sea surface temperatures in April were the second highest ever recorded. It added that recent daily measurements had continued to climb, approaching the all-time highs observed in 2024.
Samantha Burgess, strategic lead for climate at ECMWF, said the situation was developing rapidly. She warned that “it’s a matter of days before we are back in record-breaking ocean sea surface temperatures again,” highlighting the speed at which ocean warming is intensifying, according to AFP.
According to Copernicus, April’s data showed a gradual but consistent rise in ocean temperatures, particularly in regions between the tropical Pacific and the west coast of the United States, where marine heatwaves have already broken records.
The agency said this warming trend is consistent with the expected transition from neutral conditions towards an El Niño phase, which was also flagged last month by the World Meteorological Organization. The WMO has indicated that El Niño conditions could develop between May and July.
El Niño is a natural climate phenomenon characterised by changes in Pacific Ocean temperatures and trade winds. It has far-reaching effects on global weather systems, often increasing the likelihood of droughts, heavy rainfall, and other extreme weather events across different regions.
Scientists note that El Niño also contributes additional heat to a planet already experiencing long-term warming due to greenhouse gas emissions. The last El Niño event played a significant role in making 2023 and 2024 the second- and hottest years on record respectively.
Some meteorological forecasts suggest the upcoming El Niño could be particularly strong, potentially comparable to the “super” El Niño event seen three decades ago. Climate scientist Zeke Hausfather of Berkeley Earth has warned that a strong event could significantly raise the probability of 2027 becoming the hottest year ever recorded.
However, Burgess cautioned that it remains too early to accurately determine the intensity of the developing system, noting that seasonal forecasts made during the Northern Hemisphere spring are often less reliable.
Despite this uncertainty, she stressed that the impacts would be noticeable regardless of strength, adding that global temperatures are likely to remain elevated. She also suggested that 2027 could surpass 2024 as the hottest year on record, as the peak warming influence of El Niño typically occurs the year after the event itself.
Copernicus further reported that the recent increase in ocean temperatures over March and April signals a clear shift towards El Niño conditions. It also highlighted ongoing marine heatwaves and coral bleaching, warning of worsening ocean stress.
Scientists emphasise that while El Niño contributes to short-term temperature spikes, it is not the primary driver of the extreme ocean warming currently being observed. Instead, the phenomenon is occurring against the backdrop of long-term global warming, largely driven by human-induced greenhouse gas emissions. Oceans are absorbing around 90 per cent of excess heat trapped in the Earth’s system.
In its latest monthly bulletin, Copernicus stated that April ranked as the third hottest globally, registering temperatures 1.43°C above pre-industrial levels (1850–1900 baseline). It also noted that Arctic sea ice remained close to record lows during the month.
Europe, meanwhile, experienced highly variable weather conditions, which experts say may contribute to a hotter and drier summer ahead, increasing the risk of droughts and wildfires.
Burgess concluded by warning that climate extremes are becoming increasingly frequent, stating: “We just keep seeing extremes. Every month we have more data showing that climate change is driving these severe events.”
