A team of international scientist’s four-year study has revealed this week the first evidence of recent climate change, saying that it has weakened one of Earth’s natural carbon ‘sinks’ or ocean carbon dioxide (CO2) absorbers.

Like plants and trees, the ocean’s carbon dioxide sink or CO2 sink acts as a natural absorber or filtration system that inhales excess carbon dioxide from human activities such as the carbon dioxide emitted from gas powered cars, that could not be processed by plants or trees around us, leading to excess in CO2.

This is where the ocean’s CO2 sinks come in to remove the excess carbon element from that excess emission before it’s released into our atmosphere.

With the southern ocean’s inefficiency to absorb carbon dioxide, this has led to the increase of carbon dioxide into our atmosphere, consequently this will also lead to the acceleration of global warming rate, scientists say.

Published this week in the journal Science, the study by scientists from the University of East Anglia (UEA), British Antarctic Survey (BAS) and the Max-Planck Institute for Biogeochemistry also revealed that an increase in winds over the Southern Ocean, caused by greenhouse gases and ozone depletion, has led to a release of stored CO2 into the atmosphere and is preventing further absorption of the greenhouse gas.

“This is the first time that we’ve been able to say that climate change itself is responsible for the saturation of the Southern Ocean sink. This is serious. All climate models predict that this kind of ‘feedback’ will continue and intensify during this century. The Earth’s carbon sinks – of which the Southern Ocean accounts for 15% – absorb about half of all human carbon emissions. With the Southern Ocean reaching its saturation point more CO2 will stay in our atmosphere.” said lead author, Dr Corinne Le Quéré of UEA and BAS

This new research suggests that stabilisation of atmospheric CO2 is even more difficult to achieve than previously thought.

Additionally, acidification in the Southern Ocean is likely to reach dangerous levels earlier than the projected date of 2050.

Professor Chris Rapley, Director of British Antarctic Survey said “Since the beginning of the industrial revolution the world’s oceans have absorbed about a quarter of the 500 gigatons of carbon emitted into the atmosphere by humans. The possibility that in a warmer world the Southern Ocean – the strongest ocean sink – is weakening is a cause for concern.”

The saturation of the Southern Ocean was revealed by scrutinising observations of atmospheric CO2 from 40 stations around the world. Since 1981 the Southern Ocean sink ceased to increase, whereas CO2 emissions increased by 40%.