Global ocean temperatures hit record high as El Nino intensifies

What the report says

Copernicus, the European Union’s climate monitoring service, said global average sea surface temperatures reached a record high, with readings of 21.1C over Friday and Saturday, topping the previous mark set in March 2024. Al Jazeera reported that the agency linked the increase to a rapidly strengthening El Nino event layered on top of long-term warming driven by human activity.

The timing stood out because ocean temperatures typically peak in March or April, yet the new record was reached in August. Samantha Burgess of the European Centre for Medium-Range Weather Forecasts said the oceans are under growing stress, and that El Nino is adding heat to an already warmed system. The World Meteorological Organization has also said it expects El Nino to strengthen in the coming months.

The report said Copernicus expects the current El Nino to continue raising ocean temperatures until it peaks, likely between November and January. It warned that warmer oceans can contribute to sea-level rise, marine heatwaves, coral and seagrass damage, and disruption to fishing and aquaculture. Warmer water also absorbs less carbon dioxide and can add heat and moisture to the atmosphere, increasing the risk of extreme weather.

As broader context, ocean warming is widely seen by climate scientists as a major signal of climate change because it affects marine ecosystems, coastal communities and weather patterns. Jane Lubchenco, a former head of the US National Oceanic and Atmospheric Administration, told the Associated Press that an ocean this warm is troubling and can threaten food security and marine life.