Ocean Heat Record Hits 20.86°C, Scientists Warn of "Unexplored" Phase

The world's oceans have never been this hot in June. On June 21, the global sea surface temperature reached 20.86°C, according to data from Copernicus Climate Change Service and Copernicus Marine Service. This breaks the previous record of 20.83°C set in 2023 and repeated in 2024. "This record will have consequences for weather patterns, the global climate, and marine ecosystems," scientists warn. The extreme ocean heat comes from two forces: climate change and the start of an El Niño event. El Niño is a natural phenomenon where warm water builds up in the equatorial Pacific Ocean. It changes rainfall and drought patterns across much of the planet. UN Secretary-General Antonio Guterres said El Niño will "pour more gasoline on the fire of climate change." Carlo Buontempo, director of Copernicus Climate Change Service, warns the situation "could indicate the start of a new phase that takes us into unexplored territory." A warmer ocean has serious effects. Hot water evaporates more, and the warm atmosphere holds that moisture longer. This gives storms more energy. When conditions are right, rainfall becomes more extreme, raising the risk of floods. Warmer oceans also raise sea levels, melt sea ice, and disrupt marine ecosystems. Cold-water species must move or die, while tropical species expand into new areas. Carlos García-Soto, a researcher at the Spanish Institute of Oceanography, says impacts like marine heat waves, droughts, floods, fires, and crop losses are happening more at the same time. "This increases pressure on ecosystems and on our societies' ability to respond," he said. With El Niño expected to be strong this year, Copernicus predicts global temperatures will likely set new records in the coming months, both in the ocean and in the atmosphere.