The Southern Ocean, which acts as one of the natural world’s most effective sponges for absorbing carbon dioxide, is showing signs of an unexpected revival in its ability to do so, according to scientists.
The oceans absorb around a quarter of emissions caused by human activities, such as the burning of fossil fuels, reducing the speed of climate change. About 40% of this occurs in the Southern Ocean, which surrounds the Antarctic, making it the planet’s strongest ocean carbon sink.
The researchers said the new findings are surprising and remarkable.
Earlier studies had suggested that rising emissions caused by humans had brought about the saturation of the Southern Ocean in the 1980s. Researchers estimated that the efficiency of the Southern Ocean to absorb CO2 had dropped by about 30% which they put down to higher wind speeds across the area which brought carbon-rich waters to the surface. This was itself a consequence of climate change and the depletion of the ozone layer, they said, creating a feedback loop that would only get worse over time.
But the new report published in the journal Science shows that this downward trend in capacity reversed around 2002 and regained its former strength in line with rising emissions by 2012. The scientists put the change down to a combination of dropping water surface temperatures in the Pacific sector and a change in ocean circulation keeping carbon rich waters below those at the surface.
Depuis 15 ans les réchauffistes ne cessent de nous dire que le débat est clos et que les conclusions scientifiques sont définitives…
Pourtant, presque à chaque semaine, des chercheurs font la démonstration que les certitudes des réchauffistes ne tiennent pas la route !