Earth is simmering in its hottest water temps on record

The world 's ocean simmered to their hottest temperatures on record over the weekend and are likely to warm even further in the next few months, putting stress on life in water and on land.

Driven by a still growing but already supersized natural El Nino and human-caused climate change, the world's ocean temperatures hit 21.1 degrees Celsius on Friday and Saturday, narrowly edging out the record set in March 2024.

Global strategic lead at Copernicus climate service SAMANTHA BURGESS: "Corals as well as most marine organisms get incredibly stressed when the water environment is too hot for them. It also leads to fish mortality because a warmer ocean carries less nutrients and less oxygen. It changes air circulation, upwelling get less intense and we see changes in things like harmful algal blooms that impacts shellfish in particular in a warmer ocean."

The warming ocean is also reshaping currents and weather patterns, making storms rainier and larger. It also amplifies the impact of heat waves on land, as cooler nighttime temperatures, normally brought by sea breezes, become less frequent.

Global sea surface temperatures normally peak in in March and April as the southern summer draws to a close. But this year, the record was set in August, and ocean temperatures are expected to keep rising until the current El Nino reaches its peak.