The Atlantic, Mediterranean and Southern tropical oceans would have recorded the highest heat content since the 1950s in 2023, the study says. “The ocean is critical in telling us what is happening to the world, and the data paint a compelling picture of warming year after year,” said John Abraham of the University of St. Thomas in Minnesota, who was part of the team. . company that created the new data told the Guardian.
Climate researchers are particularly concerned about current temperature developments in the oceans because they are considered energy reserves: around 90 percent of the additional energy that reaches Earth due to the greenhouse effect is stored there. “Oceans are long-term storage devices. When the climate becomes unbalanced, excess energy goes into the ocean”, explains Leopold Haimberger, from the University of Vienna, to ORF.at. “It’s like going into debt, and the heat content of the ocean is the debt note.”
“El Nino” contributed to records
One of the reasons for the warming of the seas is “El Niño” – a climate phenomenon characterized by changes in sea currents and the atmosphere and by higher temperatures on the ocean surface in the Pacific. Combined with the climate anomaly, global ocean temperatures reached a record high in 2023, according to the study.
Throughout the year, the average temperature was 0.1 degrees Celsius higher than in 2022. In the second half of 2023, the temperature was also “surprisingly” 0.3 degrees Celsius higher, according to researchers.
Another consequence of the heat is the record stratification of the oceans. As a result, hot water accumulates at the surface and there is poorer exchange with the deeper layers, “as a result, less oxygen reaches the deeper layers,” says Haimberger. This, in turn, poses a challenge to marine life. High temperatures cause “adaptation stress” to species; there is already an increase in tropical species in the Mediterranean. And coral bleaching is also the result.
NOAA, NOAA Since 1955, the heat content of the oceans has increased significantly and sea temperatures are rising. To compare, move the blue button left or right.
Year full of temperature records
According to Haimberger, this year's “El Niño” was nowhere near the “Super El Niño” at the end of 2015/16 – the strongest in more than 20 years. In 2023, however, the climate anomaly developed in parallel with an unprecedented rise in global temperatures; it was already “a true El Niño year”. “Unusual circulation patterns” in Pacific riparian countries were particularly problematic. The expert describes the unprecedented drought and drought in the Amazon as a “typical consequence”.
While individual extreme events cannot be directly attributed to a specific cause, according to the Intergovernmental Panel on Climate Change, one thing is clear: the climate crisis is making extreme weather events, such as floods, storms and heat, more frequent and more intense. This means that precipitation and storms are getting stronger, heat waves are getting hotter, and droughts are getting drier.
Most likely, the meteorological phenomenon has already reached its peak and should be replaced by neutral conditions after six months. Then it depends on whether neutral conditions persist or whether “La Nina”, that is, the cold phase of the cycle, occurs from autumn onwards. However, Australia and Indonesia would likely face drought and the risk of increased wildfires for a few more months.
After “El Niño,” the North Atlantic usually becomes particularly warm because some of the energy from the Pacific reaches the Atlantic. “In this regard, it could also be extremely hot for the North Atlantic and Europe in 2024.”
The Atlantic hurricane season is also often more pronounced after “El Niño,” “so I wouldn't be surprised if particularly strong hurricanes occur there next year.” However, the consequences are complex and cannot yet be reliably predicted.
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More temperature records in 2024?
According to a report by The Washington Post, it is possible that developments around El Niño and ocean temperatures could cause average temperatures on Earth to increase by more than 1.5 degrees Celsius in 2024, for the first time in a year. pre-industrial period.
Critical threshold of 1.5 degrees almost reached in 2023
According to current data from Copernicus, the EU's Earth observation program, the critical threshold was almost reached last year. Because we're in uncharted territory, it's difficult to predict what will happen next, Copernicus director Carlo Buontempo told the Washington Post.
In any case, the global warming trend is increasing, according to Haimberger's assessment. He observes an imbalance, that is, an inequality: the Earth receives more energy than it releases into space, “this is a worrying development. We absolutely need a turnaround and the sooner we achieve it through consistent decarbonization of our activities, the better it will be for future generations.”