Oceans Absorbed Record Levels of Heat in 2025

SadaNews - A team of scientists from around the world reported yesterday, Friday, that the oceans absorbed a record amount of heat in 2025, increasing the likelihood of rising sea levels, severe storms, and coral reef death.

The accumulated heat in the oceans last year increased by about 23 zettajoules, equivalent to nearly four decades of global primary energy consumption.

The researchers noted that this result, published in the journal "Advances in Atmospheric Sciences," represents the highest annual reading since modern data recording began in the early 1950s.

To conduct these calculations, over 50 scientists from 31 research institutions utilized multiple sources, including a large array of floating robots monitoring oceanic changes to a depth of 2000 meters, as reported by the French Press Agency.

More Accurate Indicator

Karina von Schuckmann, a contributing author of the study, stated that looking at the depths of oceans instead of surface fluctuations provides a more accurate indication of how the oceans are responding to the ongoing pressure from human emissions.

The oceans are a crucial factor in regulating the Earth's climate, absorbing 90 percent of the excess heat in the atmosphere due to greenhouse gas emissions like carbon dioxide.

This additional energy has significant impacts, as rising ocean temperatures increase atmospheric humidity, providing conditions for tropical hurricanes and heavy rainfall.

Ocean warming directly contributes to rising sea levels as water expands with increased temperature, making conditions extremely difficult for tropical coral reefs that die during prolonged marine heat waves.

Von Schuckmann stated, "If heat continues to accumulate on Earth, ocean temperatures will keep rising, sea levels will rise, and new record numbers will be recorded."

Accelerated Pace

Ocean temperatures are rising in some regions at a faster pace than in others.

The tropical oceans, the South Atlantic, the Mediterranean Sea, the northern Indian Ocean, and the Southern Ocean were among the bodies of water that absorbed record amounts of heat in 2025.

This was recorded despite a slight decrease in average sea surface temperatures in 2025, yet it remained the third highest figure ever recorded.

This decline is attributed to the shift from the strong "El Niño" phenomenon, which caused warming in 2023 - 2024, to conditions similar to "La Niña," which are typically associated with temporary cooling of ocean surfaces.

In the long term, the rate of ocean warming is accelerating due to the continuous increase in greenhouse gas concentrations in the atmosphere, primarily attributed to the burning of fossil fuels.