EU climate service warns ocean heat is nearing records as El Nino builds

PARIS, France (AFP)—The European Union’s climate monitoring system reported Friday that ocean heat levels are moving back toward historic highs, as the Pacific appears to be shifting into a potentially strong El Nino phase.

Samantha Burgess of the European Centre for Medium-Range Weather Forecasts (ECMWF) said recent sea-surface readings have come very close to the peak values reached in 2024, and current trends suggest May could set a new monthly benchmark.

“It’s a matter of days before we are back in record-breaking ocean SSTs (sea surface temperatures) again,” Burgess, strategic lead for climate at ECMWF, told AFP.

The Copernicus Climate Change Service, operated under ECMWF oversight, said daily sea-surface temperatures during April steadily moved toward near-record territory, a pattern it linked to an expected El Nino transition in the months ahead.

According to Copernicus, April registered the second-highest sea-surface temperatures ever measured, and marine heatwave records were broken in waters spanning the tropical Pacific to the United States.

The World Meteorological Organization said last month that El Nino conditions could emerge between May and July. El Nino is one stage of a recurring Pacific climate cycle involving ocean temperatures and trade winds, and it can reshape weather worldwide by increasing the chances of drought, intense rainfall and other severe events.

Scientists also note that El Nino adds extra heat to a world already warmed by fossil-fuel use. The previous El Nino contributed to 2023 becoming the second-hottest year on record, followed by 2024 as the hottest.

Several forecasting centres now project the incoming episode could be stronger, with some comparisons to the “super” El Nino seen about 30 years ago. Last week, Berkeley Earth scientist Zeke Hausfather wrote that a powerful event could sharply increase the possibility that 2027 becomes the warmest year ever observed.

Burgess said confidence in intensity forecasts is still limited at this stage, because projections made in Northern Hemisphere spring can be less dependable. Even so, she said this event is expected to have clear global effects regardless of its final strength.

“We’re likely to see 2027 exceed 2024 for the warmest year on record,” she said.

She added that El Nino’s strongest influence on planetary average temperature usually appears in the year after the event reaches peak intensity.

In its latest monthly analysis, Copernicus said the rise in ocean temperatures through March and April points to a move away from neutral Pacific conditions and into El Nino.

Researchers stress, however, that El Nino is not the only force behind today’s exceptional ocean warmth or related impacts such as coral bleaching and prolonged marine heatwaves.

They say the episode is unfolding on top of long-term human-caused warming driven mainly by greenhouse gas emissions, with the oceans taking up about 90 per cent of the excess heat produced by human activity.

Copernicus also reported that April ranked as the planet’s third-hottest April, at 1.43C above the 1850-1900 pre-industrial reference level.

The service further noted Arctic sea ice remained close to record lows in April, while Europe experienced mixed weather patterns that could precede a hotter, drier summer with elevated drought and wildfire risk.

“We just keep seeing extremes. Every month we have more data that the climate change impact is creating these extreme events,” Burgess said.