PARIS: With sea surface temperatures increasing to new highs in recent weeks, scientists and researchers warn that humanity’s carbon pollution has the full potential to turn seas into a global warming “time bomb.”
Oceans absorb most of the heat generated by planet-warming gases, creating heatwaves that harm aquatic life, altering weather systems, and disrupting important planet-regulating systems.
While ocean surface temperatures normally decrease relatively quickly from annual peaks, this year they stayed up, with scientists warning that this highlights an underappreciated but serious impact of climate change.
French research agency CNRS’s leading oceanologist Jean-Baptiste Sallee said that the ocean, like a sponge, absorbs over 90 percent of the increase in heat caused by human activities. Year by year, ocean warming is exacerbating, he told AFP.
The sea temperature in April
In early April, the average surface temperature of seas, excluding polar waters, went up to 21.1 degrees Celsius, beating the annual record of 21 Celsius set in March 2016, according to the United States NOAA observatory’s data that goes back to 1982.
Although temperatures started to drop at the end of April, they have remained above seasonal records for the past 6 weeks, with fears that the expected warming El Nino weather phenomenon could bring even more heat into the climate system.
The most immediate effect of the surge in sea temperatures is more marine heatwaves, which the scientist said “act like underwater fires” with the full potential to irreversibly degenerate thousands of square kilometers of the underwater forest — for example, of corals or kelp.
Higher ocean surface temperatures disturb the mixing of nutrients and oxygen important for supporting life and likely alter the sea’s crucial role in absorbing carbon from the atmosphere.
CNRS’s oceanologist Catherine Jeandel said that as the water is warmer, there would be high evaporation and an increased risk of more intense cyclones and perhaps effects on ocean currents.
Scientists expect increased heat stored in the world’s waters to be returned to the Earth’s system and contribute to more global warming.
