Ocean Surface Temperatures Hit Record High on June 21, Raising Climate Concerns

MUMBAI — Global ocean surface temperatures outside the polar regions reached a record high on June 21, surpassing previous records and sparking warnings from scientists about intensifying extreme weather. According to the Copernicus Climate Change Service, the sea surface temperatures exceeded the previous highs recorded on the same date in 2023 and 2024, threatening weather patterns, global climate systems, and marine ecosystems.

The record-breaking temperatures are expected to coincide with the early stages of an El Niño event, which forecasters predict could be the strongest in decades. This combination is expected to fuel extreme weather events worldwide, including heatwaves, floods, and storms.

The Copernicus Climate Change Service, which is part of the European Union's space programme, reported the new peak on Wednesday. Scientists had previously described the June 2023 ocean temperature record as "worrying" and "terrifying" because it far exceeded expectations. That period preceded a major El Niño event and a series of devastating global heatwaves, floods, and storms.

Now, those 2023 records have been surpassed. Many regions are already witnessing rising temperatures. Last month, the United Kingdom and several European countries experienced record heat, while Antarctica recorded unusually mild winter conditions.

While land temperatures often receive greater public attention, scientists emphasize that ocean temperatures provide a much clearer measure of the Earth's warming. Oceans absorb more than 90 percent of the excess heat generated by human-caused warming, primarily driven by the burning of fossil fuels such as oil, coal, and gas. Last year, the resulting energy imbalance in the oceans reached a record 23 zettajoules, which is more than double the average recorded over the previous two decades.

The pace of ocean warming is accelerating rapidly. In 2020, the heat absorbed by the oceans was equivalent to about five Hiroshima bombs exploding every second. By last year, that figure had escalated to nearly 11 Hiroshima explosions per second. The rapid heating prompted United Nations Secretary-General António Guterres to warn that the "Earth is being pushed beyond its limits."

Although annual ocean temperature peaks are typically recorded in July and August, making it too early to determine if the latest rise will be temporary, experts remain concerned. Carlo Buontempo, Director of the Copernicus Climate Change Service at the European Centre for Medium-Range Weather Forecasts, warned that more records could fall soon.

"With ocean temperatures at these levels and El Niño on the horizon, we are likely to see more temperature records fall in the coming months," Buontempo said.