The Southern Ocean is the world’s most effective basin of carbon dioxide absorption, and recently, it has been showcasing a renewed strength in this ability.
Southern Ocean: A Natural CO2 Vacuum
The world’s oceans absorb around a quarter of emissions caused by human activities, such as the burning of fossil fuels. 40% of this absorption occurs in the Southern Ocean, which surrounds the Antarctic.
The natural process is pivotal as it reduces the speed of climate change: carbon dioxide, in this cycle, gets soaked in from the air and is then released by the ocean every year. Re-uptake frequently occurs, but even so, the Southern Ocean remains the planet’s strongest ocean carbon sink.
Earlier studies have suggested that rising emissions have reduced the Southern Ocean’s ability to absorb carbon dioxide by 30%, due to over-saturation of the body of water during the 1980s. As reported by Science Magazine, however, the downward slope has finally made a turnaround.
According to scientists, the Southern Ocean’s increased rate of carbon absorption is due to the drop in water surface temperatures in the Pacific, combined with ocean circulation changes, which once kept carbon-rich waters below the surface of the sea. The trend began in 2002, slowly regaining its strength, until emissions started to increase noticeably in 2012.
The Increased Activity May Be Ephemeral
Environmental Physicist and author, Professor Nicholas Gruber, commented on the development, stating that a strong carbon sink in the Southern Ocean definitely helps to mitigate climate change, even if this effect is temporary.
Because the Southern Ocean is more variable than initially thought, researchers cannot conclude whether or not the upward trend will continue to occur. Previous research was largely dependent on models, rather than observations, and that may have resulted in inaccurate conclusions regarding the rise and decline of the Southern Ocean’s rate of carbon absorption. Furthermore, emissions have gone up within the last couple of years, despite the good news.
At the moment, there is also an ongoing debate about how the acidity of the water – with its increased carbon dioxide levels – may negatively affect sea creatures in the ocean. For example, crabs, lobsters and mussels may experience difficulty growing their protective shells, making them vulnerable to predators. A new study suggests that this should not be a major concern, since the acidity is plunged deep into the ocean after it is sucked in; future tendencies, however, cannot always be accurately predicted.
