Global Sea Surface Temperatures Hit Record High in June

The European climate monitoring agency, the Copernicus Climate Change Service, has revealed that global sea surface temperatures hit a record in June. The findings have sparked concerns about subsequent heatwaves this summer.

Copernicus Climate Change Service noted that on 21 June, the global sea surface temperature, excluding polar waters, surpassed the record recorded in the same period in 2023 and 2024. The agency warned that this new record will impact weather patterns, the global climate, and marine ecosystems.

This condition occurs during the early phase of the El Niño phenomenon, which is expected to be one of the strongest in recent decades. Previously, the hottest sea surface temperature record was set in June 2023. At that time, scientists described the rising sea surface temperature trend as ‘terrible’ and ‘frightening’ because it exceeded previous forecasts. Rising sea surface temperatures are an indicator of El Niño, heatwaves, floods, and storms.

‘With sea surface temperatures rising at this level and El Niño on the horizon, we are likely to see new records in the coming months,’ said Carlo Buontempo, Director of the Copernicus Medium-Range Weather Forecasting Centre, as quoted by The Guardian on Thursday.

Last month, a heatwave broke air temperature records in the UK and several European countries. Meanwhile, Antarctica experienced an unusually warm winter.

Scientists and governments typically focus more on land temperatures. However, sea surface temperatures provide a picture of how global warming, triggered by greenhouse gas emissions from human activities, is affecting the global climate. Sea surface temperatures are influenced by solar radiation, ocean currents, and the accumulation of heat in the deep ocean. The oceans absorb more than 90 percent of the excess energy in the Earth’s system. This excess energy is primarily caused by the burning of fossil fuels, such as oil, coal, and gas.

This energy imbalance reached a record high of 23 zettajoules last year. That amount is more than double the average over the previous two decades. This condition is accelerating the warming of the sea surface. In 2020, the amount of heat entering and stored in the oceans was equivalent to the explosion of about five Hiroshima atomic bombs every second. Scientists say it is too early to determine whether the sea surface warming is temporary or will worsen, as the Earth’s peak temperatures are usually recorded in July and August.