The world’s oceans, which have absorbed much of the extreme heat caused by humanity’s carbon pollution, continued to see record-breaking temperatures last year, according to research published Wednesday.
Climate change has increased surface temperatures across the planet, leading to atmospheric instability and increasing extreme weather events such as storms.
The oceans absorb about 90 percent of the excess heat from greenhouse gas emissions, producing huge, prolonged marine heat waves that have already devastating effects on underwater life while protecting land surfaces.
The study, by researchers in China, the US, Italy and New Zealand, said 2022 was the “warmest year recorded in the world’s oceans”.
According to the authors, the heat content in the oceans exceeded the previous year’s levels by about 10 Zetta joules – equivalent to 100 times the worldwide electricity production in 2021.
“The oceans absorb most of the warming from human carbon emissions,” said co-author Michael Mann, a professor at the University of Pennsylvania.
“Until we reach net zero emissions, this heating will continue and we will continue to break ocean heat content records as we did this year,” he said. “Better awareness and understanding of the oceans is the foundation of actions to combat climate change.”
Records dating back to the late 1950s show a relentless rise in ocean temperatures, with nearly continuous increases going back to 1985.
– ‘Nightmare for marine life’ –
Scientists have warned that rising temperatures are creating major changes in ocean stability faster than previously thought.
The research, published in the journal Advances in Atmospheric Sciences, was based on observations by 24 scientists from 16 institutes around the world.
It also found other indications that ocean health was deteriorating.
Rising water temperatures and ocean salinity – again at an all-time high – directly contribute to a “stratification” process in which water is split into layers that no longer mix.
This has far-reaching implications because it affects the exchange of heat, oxygen, and carbon between the ocean and the atmosphere, with effects including loss of oxygen in the ocean.
“Deoxygenation itself is a nightmare not only for marine life and ecosystems, but also for humans and our terrestrial ecosystems,” the researchers said in a statement.
According to Europe’s Copernicus Climate Change Service, updated data released this week showed that average global atmospheric temperatures through 2022 were the fifth warmest year since the 19th century when records began.
Countries around the world have faced unprecedented natural disasters that have become more likely and deadly due to climate change.
Many of these effects can be attributed to a rapidly warming ocean and related changes in the hydrological cycle.
“Some places are experiencing more drought, which increases the risk of wildfires, and other places experience massive floods from heavy rainfall, often supported by increased evaporation from warm oceans,” said co-author Kevin Trenberth of the US National Center. For Atmospheric Research and the University of Auckland.