World’s oceans reach record-breaking temperatures for sixth year in a row

By Georgia Lambert via SWNS

The world's oceans are hotter than ever before - reaching record-breaking temperatures for the sixth year in a row, warns new research.

Researchers from 14 institutes around the world found that seas are still getting hotter despite the United Nations' intergovernmental efforts to "maintain human societies and natural ecosystems."

Drawing from two vast, international datasets from the Chinese Academy of Sciences (CAS), and the National Oceanic and Atmospheric Administration (NOAA), the report analyzed how the temperature of our oceans has impacted the planet since the 1950s.

Study author Dr. Kevin Trenberth from the National Center for Atmospheric Research in Colorado, said: “The ocean heat content is relentlessly increasing, globally, and this is a primary indicator of human-induced climate change.

“In this most recent report, we updated observations of the ocean through 2021, while also revisiting and reprocessing earlier data.”

Using a unit of electrical energy called a Zettajoule, the team explained that in a single year, people all over the world use up about half of a Zettajoule.

Whereas in comparison to the upper 2,000 meters of the world's oceans, the team found that the shallow sea levels had absorbed 14 more Zettajoules than in 2020.

This huge increase in electrical energy usage is equal to 145 times the world electricity generation in 2020.

Lead author, Professor Lijing Cheng from the International Centre for Climate and Environmental Sciences at CAS, said: "As well as absorbing heat, currently, the ocean absorbs 20 to 30 percent of human carbon dioxide emissions, leading to ocean acidification; however, ocean warming reduces the efficiency of oceanic carbon uptake and leaves more carbon dioxide in the air."

Professor Cheng, who teaches at the university's Institute of Atmospheric Physics, added: “Monitoring and understanding the heat and carbon coupling in the future are important to track climate change mitigation goals."

The researchers assessed the role of natural variations, such as the warming and cooling phases - known as El Niño and La Niña - which greatly affect regional temperature changes.

According to Professor Cheng, these regional analyses have proved that ocean warming since the 50s, has occurred everywhere.

This warming has had a knock-on effect that has caused heatwaves to occur beneath the surface, which has had a devastating effect on marine life.

Professor John Abraham who teaches at the University of St Thomas in Minnesota, said: “Our previous work showed that scientists need less than four years of ocean heat measurements to detect a human-induced warming signal from natural variations.

"This is much shorter than the nearly three decades of measurements required to detect global warming using temperatures of air near the Earth’s surface.

"Indeed, although in the top ten warmest years, global surface temperatures for 2021 are not the highest on record because of La Niña conditions in the tropical Pacific, among other things."

Professor Abraham went on to confirm that "ocean heat content is one of the best indicators of climate change.”

According to the researchers, during La Niña, the ocean buries extra heat below the surface.

Dr. Cheng said: “With model experiments, our study shows that the pattern of ocean warming is a result of human-related changes in atmospheric composition.

“As oceans warm, the water expands and sea level rises. Warmer oceans also supercharge weather systems, creating more powerful storms and hurricanes, as well as increasing precipitation and flood risk.”

Another of the paper's authors, Michael Mann, a Distinguished Professor of Atmospheric Science at Pennsylvania State University confirmed the role that we have in curbing this crisis.

He said: "The oceans are absorbing most of the heating from human carbon emissions.

“Until we reach net-zero emissions, that heating will continue, and we’ll continue to break ocean heat content records, as we did this year.

"Better awareness and understanding of the oceans are a basis for the actions to combat climate change.”

The report was published in the journal Advances in Atmospheric Sciences.