World oceans absorbed record heat in 2025, may trigger intense climate crises, says report

In the latest scientific study, researchers have revealed some shocking facts about world oceans that may trigger worst climate crises or extreme weather conditions.

A team of international scientists revealed on Friday, January 9, 2026, that the world's oceans had absorbed a record amount of heat in 2025, reports AFP.

The alarming situation had created a priming condition for sea level rise, violent storms, and coral death.

The heat that accumulated in the oceans last year increased by approximately 23 zettajoules—an amount equivalent to nearly four decades of global primary energy consumption.

According to researchers, the latest findings published in the journal Advances in Atmospheric Sciences—the highest reading of any year since modern record keeping began in the early 1950s.

To derive these calculations, more than 50 scientists from 31 research institutions used multiple sources including a thousands-strong fleet of floating robots that track ocean changes to depths of 2,000 meters.

Co-author of the study, Karina von Schuckmann, informed that "peering into the depths, rather than at the fluctuations on the surface, provides a better indicator of how oceans are responding to sustained pressure from humanity´s emissions."

Von, oceanographer from French research institute Mercator Ocean International told AFP that, "The picture is clear and results for 2025 confirm that the ocean continues to warm."

As per scientists, oceans are a key regulator of Earth's climate because they soak up 90 percent of the excess heat in the atmosphere caused by humanity's release of greenhouse gases like carbon dioxide.

All that additional energy has a powerful knock-on effect as warmer oceans increase moisture in the atmosphere, providing fuel for tropical cyclones and destructive rainfall.

Researchers inform that hotter seas also directly contribute to sea level rise as water expands when it warms up and makes conditions unbearable for tropical reefs, whose corals perish during prolonged marine heatwaves. "As long as the Earth continues to accumulate heat, ocean heat content will keep rising, sea level will rise and new records will be set," said von Schuckmann.

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

This occurred even as average sea surface temperatures decreased slightly in 2025—yet still remained the third-highest value ever measured.

This decrease is explained by the shift from a powerful, warming El Nino event in 2023-2024 to La Nina-type conditions generally associated with a temporary cooling of the ocean surface.

In the long term, the rate of ocean warming is accelerating due to a sustained increase in greenhouse gas concentrations in the atmosphere caused mainly by burning fossil fuels.

As long as global warming is not addressed and the amount of heat trapped in the atmosphere keeps rising, oceans will keep breaking records, the researchers said.

"The greatest uncertainty in the climate system is no longer the physics, but the choices humanity makes," said Von Schuckmann.

"Rapid emission reductions can still limit future impacts and help safeguard a climate in which societies and ecosystems can thrive," Von added.