The ocean just broke a temperature record that may have stood for millennia

 

From WP by Ben Noll

Marine heat waves currently cover 42 percent of the planet’s oceans.

As a record-breaking El Niño builds in the Pacific and large swaths of the globe’s oceans are affected by marine heat waves, a significant record has fallen.

According to data from the Copernicus Climate Change Service, average global sea surface temperatures have reached a new high, rising to nearly 70 degrees Fahrenheit late last week — potentially for the first time in millennia.

 

This mark surpassed the previous record set in March 2024.

“August 21st likely marked the warmest Sea Surface Temperatures have been for the entire Holocene period, and possibly even as far back as the last Interglacial 125,000 years ago,” wrote University of Ottawa professor Ryan Katz-Rosene on X.
Sea surface temperatures from thousands of years ago are reconstructed using marine sediment cores, which contain tiny fossils whose chemistry reflects the temperature of the water in which they formed.

These records indicate that global sea surface temperatures are now higher than at any time in at least 12,000 years and are probably reaching levels experienced during the last interglacial period, around 123,000 to 128,000 years ago.
The unusual ocean warmth has fueled powerful storms in the Pacific, such as Hurricane Lala near Hawaii, helped create a reservoir of extra moisture that has contributed to recent rainfall extremes across the United States and boosted summer heat across Europe.

About 42 percent of the planet's oceans are currently covered by marine heat wave conditions. Marine heat waves are marked by unusual and persistent ocean warmth compared to average. 

(Ben Noll/The Washington Post; NOAA)

According to NOAA data, 42 percent of the planet’s oceans are currently experiencing marine heat waves.

In the Pacific Ocean alone, marine heat waves cover an area that’s equivalent to nine times the size of the contiguous United States — greatly contributing to the new global sea surface temperature record. 

 

Links :

• BBC : World's oceans hit highest temperature on record as El Niño grows
• Copernicus: Daily global sea surface temperature breaks 2024 record
• The Guardian : World’s oceans hit hottest temperature on record in August 
• Scientific American : Earth’s oceans just hit their hottest temperature ever—it’s only going to get worse