A new study has found that the rate of ocean warming has more than quadrupled since the late 1980s. This means the oceans are heating up much faster than before, which has serious consequences for our planet.
The study, published on January 28, 2025, in Environmental Research Letters, helps explain why 2023 and early 2024 recorded the hottest ocean temperatures in history.
How fast are oceans warming?
In the late 1980s, ocean temperatures were rising at 0.06°C per decade. But now, they are warming at 0.27°C per decade—more than four times faster.
Professor Chris Merchant, the lead author from the University of Reading, compared this warming to filling a bathtub with hot water:
“In the 1980s, the hot tap was running slowly, warming the water very little each decade. But now, the hot tap is running much faster, making the warming speed up. The way to slow this down is to start turning off the hot tap—by cutting carbon emissions and moving towards net-zero.”
Why are the oceans getting warmer?
The main reason for this accelerating ocean warming is the Earth’s energy imbalance. This happens when:
- More heat from the sun gets trapped in the Earth’s system than escapes back into space.
- Greenhouse gases, like carbon dioxide (CO₂), are increasing, making the planet absorb more heat.
- The Earth is reflecting less sunlight away, meaning more heat stays within the atmosphere and oceans.
Since 2010, this energy imbalance has doubled, leading to faster ocean warming.
In 2023 and early 2024, global ocean temperatures reached record highs for 450 days straight.
Some of this was caused by El Niño, a natural warming event in the Pacific Ocean. But scientists found that El Niño wasn’t the only reason—44% of the record warmth was due to oceans absorbing heat at an accelerating rate.
The study warns that ocean warming in the next 20 years could be greater than in the past 40 years. Since oceans control the Earth’s climate, this means:
- Stronger storms and hurricanes
- Rising sea levels and coastal flooding
- Heatwaves that harm marine life and coral reefs
Scientists say the best way to slow down ocean warming is to reduce fossil fuel use and transition to clean energy sources like solar and wind power.
If we take action now, we can stabilize the climate and protect our oceans. The future of our planet depends on the choices we make today.
Source: University of Reading.
