As greenhouse gas emissions increase, warnings about an increase in ocean warming are bound to follow. Now, a new study has found that ocean warming has dramatically accelerated in recent decades and revealed the locations with the greatest heat uptake.
The study, published recently in Nature Communications, reveals that ocean warming has nearly doubled between 2010 and 2020 compared to the 1990-2010 period. Led by researchers at the University of New South Wales (UNSW Sydney), the study also showed that some areas of the ocean are taking on more of the absorption work, a press release said.
Rising amounts of greenhouse gases in the air, a consequence of human activity, trap heat within the climate system, warming air, the land surface, the oceans, and melting polar ice. However, oceans end up doing the majority of the work, absorbing more than 90% of the excess heat. Although ocean warming helps in slowing down climate change, it comes at a cost, the researchers explain in the statement.
“The world ocean, in 2023, is now the hottest ever recorded, and sea levels are rising because heat causes water to expand and ice to melt,” study author Mathew England says. “Ecosystems are also experiencing unprecedented heat stress, and the frequency and intensity of extreme weather events are changing rapidly, and the costs are enormous.” In this study, the researchers wanted to understand where the ocean heat uptake has been occurring.
While ocean warming was been widespread, the researchers found that its distribution by region was not uniform. The Southern Ocean saw the largest increase in heat storage over the past two decades, almost the same excess anthropogenic heat as the Atlantic, Pacific, and Indian Ocean combined, the statement explained. This includes two huge masses of water in the Southern Ocean that combine to fill a depth range of 300 to 1500 metres.
“Melting ice caps, extreme weather, and marine ecosystems, including coral reefs, are all highly sensitive to ocean temperature changes,” study author Sjoerd Groeskamp adds in the statement. It is important to understand how and where ocean warming occurs, Groeskamp added.
In their statement, the researchers also said that there is a pressing need to increase monitoring of global oceans, specifically in remote locations such as the polar oceans and key regions of the subtropical and coastal areas. Without any action, these net zero pledges are just meaningless, Groeskamp said.