Record surface heat could turn oceans into global warming 'time bomb'

The most immediate consequence of the surge in ocean temperatures are marine heatwaves, which "act like underwater fires" with the potential to irreversibly degrade thousands of square kilometres of underwater forest. © Reuters - Lucas Jackson

With sea surface temperatures swelling to new highs in recent weeks, scientists warn that humanity's carbon pollution has the potential to turn oceans into a global warming "time bomb".

"The ocean, like a sponge, absorbs more than 90 percent of the increase in heat caused by human activities," said leading oceanologist Jean-Baptiste Sallee, of the French research agency CNRS.