Record sea surface heat sparks fears of warming surge
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".
Oceans absorb most of the heat caused by planet-warming gases, causing heatwaves that harm aquatic life, altering weather patterns and disrupting crucial planet-regulating systems.
While sea surface temperatures normally recede relatively quickly from annual peaks, this year they stayed high, with scientists warning that this underscores an underappreciated but grave impact of climate change.
"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.
Year by year ocean warming is increasing at "an absolutely staggering rate", he told AFP.
In early April, the average surface temperature of the oceans, excluding polar waters, reached 21.1 degrees Celsius, beating the annual record of 21C set in March 2016, according to data from the United States NOAA observatory that goes back to 1982.
Rising sea surface temperatures threatens severe consequences for life in and out of the oceans.