New Delhi: The rate of ocean warming has more than quadrupled over the past four decades, according to a new study on Tuesday, explaining why 2023 and early 2024 saw unprecedentedly high sea temperatures.
The study, published in the journal Environmental Research Letters, showed that ocean temperatures were rising at about 0.06 degrees Celsius per decade in the late 1980s. However, they are currently increasing at 0.27 degrees Celsius per decade.
“If the oceans were a bathtub of water, then in the 1980s, the hot tap was running slowly, warming up the water by just a fraction of a degree each decade. But now the hot tap is running much faster, and the warming has picked up speed,” said lead author Professor Chris Merchant, at the University of Reading, UK.
Merchant said that cutting global carbon emissions and moving towards net zero is the only way to slow down warming. In 2023 and early 2024, global ocean temperatures hit record highs for straight 450 days.
Besides El Nino, a natural warming event in the Pacific, the team found that the sea surface warming went up faster in the past 10 years than in earlier decades. The study noted that about 44 per cent of the record warmth was attributable to the oceans absorbing heat at an accelerating rate.
The findings show that the overall rate of global ocean warming observed over recent decades is not an accurate guide to what happens next: it is plausible that the ocean temperature increase seen over the past 40 years will be exceeded in just the next 20 years.
Because the surface oceans set the pace for global warming, this matters for the climate as a whole, the team explained.
This accelerating warming underscores the urgency of reducing fossil fuel burning to prevent even more rapid temperature increases in the future and to begin to stabilise the climate.
Warming ocean temperatures can increase the spread of diseases in marine species. This in turn can affect humans, when consuming marine species, or from infections of wounds exposed in marine environments.
