Ocean surface temperatures reach a record high for June

Ocean surface temperatures have reached a record high, causing worries about more extreme heat this summer.

On 21 June, temperatures in areas outside the polar regions were higher than the record highs seen at the same time in 2023 and 2024, according to the Copernicus Climate Change Service. They announced this on Wednesday.

The service warned that this new high temperature is likely to have consequences for weather patterns, the global climate, and sea life. This is partly because it comes at the same time as the early stages of an El Niño event, which is predicted to be the strongest in many years.

When the previous ocean record for June was set in 2023, scientists called the trends worrying and surprising because they were much higher than expected. This was followed by an El Niño and a period of severe heatwaves, floods, and storms around the world.

That 2023 record has now been broken, and large parts of the world are again experiencing a worrying increase in temperatures. Last month, the UK and many other European countries experienced record heat, while Antarctica had unusually warm winter conditions.

Although people often focus on land temperatures, oceans provide a better picture of how human-caused warming is affecting the Earth’s balance. Surface temperatures are influenced by sunlight, ocean currents, and heat stored in the deeper parts of the ocean.

Oceans absorb over 90% of the extra energy in the Earth's system. This extra energy mainly comes from burning fossil fuels like oil, coal, and gas. This imbalance reached a record high of 23 zettajoules last year, more than double the average amount seen in the past twenty years.

As a result, oceans are warming faster and faster. In 2020, the amount of heat added to the oceans each second was like exploding five Hiroshima bombs. Last year, it was closer to 11 Hiroshima explosions per second. The UN's secretary general, António Guterres, has warned that the Earth is being pushed beyond its limits.

Scientists have stated that it is too early to know if the warming of the sea surface will be temporary or get worse. Usually, the highest temperatures are seen in July and August.

However, Carlo Buontempo, director of Copernicus at the European Centre for Medium-Range Weather Forecasts, warned that this could signal the start of a new phase. He believes that with ocean temperatures at these levels and an El Niño approaching, more temperature records are likely to be broken in the coming months.

Copernicus is part of the EU's space program.