Record sea temperatures in June push world into ‘uncharted’ waters
Global warming and El Niño cycle combine to drive average to near 21C
A record global average sea temperature in June had pushed the world into “uncharted territory,” scientists said, as global warming and the El Niño cycle combine to increase the chances of more extreme weather ahead.
The daily sea surface temperature had surpassed the previous highs in the same month in 2023 and 2024, two European earth observation agencies confirmed.
It reached 20.96C on June 21, according to the EU’s Copernicus Climate Change Service, while this figure was put at 21C by Copernicus Marine.
The new record came just weeks after the National Oceanic and Atmospheric Administration said the naturally occurring El Niño weather phenomenon had developed, with waters in the central and eastern tropical Pacific Ocean near the equator becoming significantly warmer.
“[The] unprecedented level of warming of the global extrapolar ocean” in June reflected both the “changing climate and the onset of an El Niño event whose strength . . . is likely to reach levels not seen in decades,” the European agencies said.
Carlo Buontempo, Copernicus Climate Change Service director, said the conditions “could indicate the beginning of a new phase, leading, once more, to uncharted territory”.
“With ocean temperatures at these levels and El Niño on the horizon, we are likely to see more temperature records fall in the coming months.”
During the last El Niño event from 2023 into 2024, global sea temperature repeatedly breached monthly highs. The cycle is linked with more extreme weather events, including flood and droughts in different parts of the world.
Higher ocean temperatures can mean the atmosphere stays warmer for longer, while also providing extra energy and moisture for storms.
The oceans have absorbed about 90 per cent of the world’s excess heat and about a quarter of human-caused carbon dioxide produced during the industrial era. Scientists are monitoring whether they may be reaching their limits.
Europe has experienced a severe heatwave in recent weeks, with new June air temperature records set in countries including the UK, France and Germany. The World Health Organization said the extreme weather had led to 1,300 excess deaths and caused school closures and rail disruption.
Michael Meredith, an oceanographer at the British Antarctic Survey in Cambridge, said the latest June sea temperature record was “very concerning”.
While El Niño’s cycle was still in its early stages and not yet the dominant driver of global temperatures, he said, conditions could worsen significantly.
The global average temperature rise during the industrial era is estimated at about 1.4C by the World Weather Attribution scientific research group.
“The major concern is that the long-term warming trend, combined with shorter-term climate fluctuations, will drive more extreme weather, place additional stress on already-pressured ecosystems, and increase climate risks across the globe,” Meredith said.