Ocean Temperatures Hit Record High as El Nino Intensifies

Drivers of the Warming

The added heat from El Nino, a natural temporary warming of parts of the Pacific that warps weather and raises temperatures globally, is occurring on top of long-term warming driven by fossil fuels. Burgess noted that human-driven warming has already raised ocean temperatures by 0.8C (1.44F).

"This record is another clear signal of an ocean under growing stress," Burgess said. "El Nino is adding heat to the system, but it is doing so on top of decades of human-driven warming."

Consequences for Marine Life and Climate

Copernicus warned that rising ocean temperatures have "far-reaching consequences" for marine ecosystems and coastal communities. Warmer oceans contribute to sea-level rise through thermal expansion and increase the likelihood and intensity of marine heatwaves, which can damage coral reefs and seagrass beds. This disruption can ripple through food chains and threaten industries such as fishing and aquaculture.

Warmer oceans are also less able to absorb carbon dioxide, weakening one of the planet's key defences against climate change. Higher ocean temperatures can additionally supply more heat and moisture to the atmosphere, enhancing the "potential for extreme weather events."

Jane Lubchenco, an oceanographer and former head of the US National Oceanic and Atmospheric Administration, called the finding "very troubling." She said an ocean this warm "destabilises weather patterns and threatens food security, economic prosperity and marine life," adding that "a warmer ocean is not our friend."

What Lies Ahead

With El Nino expected to strengthen through the coming months and peak between November and January, ocean temperatures are likely to continue rising. Authorities have not confirmed when the current warming trend will ease, and additional data on the event's full impact on marine ecosystems and weather systems is still awaited.