New results from an international team of researchers show that record ocean temperatures are continuing as climate change shows no sign of stopping

A continued record-breaking ocean temperature, with increasing changes in stratification and water salinity patterns, gives insight into what the future holds amidst a perpetually heating climate.

The oceanic observations of 24 scientists from 16 institutes worldwide has further highlighted concerns over the state of our oceans at a time of unfettered global warming. The three key indicators of climate change include continued historical record-breaking temperatures, all-time high levels of ocean salinity contrast, and increased ocean stratification (separation of the water into layers) with no signs of slowing down.

These indicators are leading scientists to quickly address and forecast future components of climate change to better prepare the public for an extreme climate future.

Lijing Cheng, lead author and researcher for the Institute of Atmospheric Physics (IAP) at the Chinese Academy of Sciences (CAS), said: “Global warming continues and is manifested in record ocean heat, and also in continued extremes of salinity. The latter highlights that salty areas get saltier, and fresh areas get fresher and so there is a continuing increase in intensity of the hydrological cycle.”

See also: Climate change leading to acidification of Arctic Ocean


The increasing saltiness and therefore stratification of the oceans can alter how heat, carbon and oxygen are exchanged between the ocean and the atmosphere above it. This is a factor that can cause ocean deoxygenation, or loss of oxygen, within the water.

Deoxygenation itself is a nightmare not only for marine life and ecosystems but also for humans and our terrestrial ecosystems.

Reducing oceanic diversity and displacing important species can wreak havoc on fishing-dependent communities and their economies, and this can have a ripple effect on the way most people are able to interact with their environment. Some places are already seeing the impacts of a rapidly warming ocean, and they’re not exactly as expected.

Kevin Trenberth, third author of the paper and researcher at both the National Center for Atmospheric Research, USA, and the University of Auckland, New Zealand, said: “Some places are experiencing more droughts, which lead to an increased risk of wildfires, and other places are experiencing massive floods from heavy rainfall, often supported by increased evaporation from warm oceans.

“This contributes to changes in the hydrologic cycle and emphasises the interactive role that oceans play.”

net zero emissions

An increase in water temperatures and salinity directly contributes to water layering instead of mixing, and this is just part of what throws off the delicate balance between our oceans and the atmosphere.

Professor John Abraham, of the University of St Thomas, USA, is the second author of the study. He said: “In the future, the group will focus on understanding the changes of the Earth’s major cycles and improve the future projections of Earth’s heat, water and carbon changes.

“This is the basis for humans to prepare for the future changes and risks.”

Continued tracking of these changes will give scientists an idea of what can be done pre-emptively to prepare for higher temperatures, extreme weather, and all other consequences that come with warming oceans and an impacted hydrologic cycle.

Paper author Professor Michael Mann, of the University of Pennsylvania, USA, added: “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 results are published in Advances in Atmospheric Science. 

Image: The oceans are home to millions of Earth’s plants and animals. People travel on the ocean and rely on the resources it contains. © Lijing Cheng.