Oceans on the Verge of Breaking Temperature Records
As global temperatures continue to rise, the world’s oceans are nearing an unprecedented heat milestone. Such warming poses significant threats to marine ecosystems and the ocean’s ability to absorb carbon dioxide from the atmosphere, according to climate experts.
“It just spells trouble for the planet,” remarked Kristina Dahl, a climate scientist at Climate Central, a non-profit based in Princeton, New Jersey.
Data from the European Commission’s Copernicus Climate Change Service reveal that sea surface temperatures, influenced by human-induced climate change and a robust El Niño event, have exceeded monthly records over the past two months. July’s average sea surface temperature outside polar regions was recorded at 20.96 °C, overtaking the previous July record by 0.07 °C. This follows a record-breaking June.
The oceans are on the brink of surpassing historical temperature peaks, with current averages just shy of the March 2024 record. Given El Niño’s ongoing influence, breaking this record seems imminent. “It’s just a case of when,” noted Samantha Burgess, Copernicus’ deputy director.
El Niño is driving much of this heat, with an expansive warm water band in the tropical Pacific. However, additional regions, including parts of the northern Pacific, Atlantic, and the Mediterranean, are also experiencing abnormal warmth compared to the pre-2020 average.
An analysis tool by Climate Central highlights that human-induced climate change has significantly increased the likelihood of high ocean temperatures. “Basically, everywhere on Earth, we’re having above-normal temperatures in the ocean,” Dahl stated.
Deja Vu in Oceanic Heat
The recent heatwave follows record sea temperatures in 2023 and 2024, fueled by an El Niño combined with global warming. The unexpected temperature surge has led scientists to question whether the planet’s climate sensitivity is greater than current models suggest. “We don’t know why the ocean has behaved differently for the last four years,” Burgess commented.
This year, temperatures have surpassed previous records by a smaller margin. Jens Terhaar, an ocean modeller from the University of Bern, suggests this will likely spark further debates on climate sensitivity. “It should definitely ring some alarm bells,” he expressed.
The repercussions of elevated ocean temperatures are vast, affecting fisheries, such as anchovy declines off South America’s Pacific coast due to El Niño. Marine heat waves also impact coastal communities, increasing temperatures and humidity, especially overnight.
Coral reefs are among the most vulnerable to these rising temperatures. Amy Apprill, a marine geochemist at the Woods Hole Oceanographic Institution, emphasized, “It’s basically a terrifying time for corals and coral-reef ecosystems.”
Original Story at www.nature.com