Atmospheric carbon dioxide is being pushed deeper into the oceans than previously thought, according to researchers.
The findings mean the oceans may continue to absorb human emissions of the greenhouse gas more rapidly and for longer, they say, reducing their impact on global warming. But the research is bad news for the marine organisms that are already suffering from ocean acidification....
"Previous estimates, based on educated assumptions about what the pre-industrial oceans looked like, suggested that in the high latitudes of the North Atlantic, anthropogenic CO2 was not found below 2500 metres," says Douglas Wallace of the University of Kiel, Germany.
Wallace and colleagues have now published the first measurements showing the location of CO2 from human activities in the North Atlantic. They used data collected during a research cruise in 1981 as a baseline, and then returned to exactly the same sampling locations in 2004.
"This revealed quite large changes in the CO2 in very deep water, between 3000 m and 5000 m," Wallace told New Scientist.
Dissolving depth If their findings are replicated in the much bigger southern oceans, it could mean that the oceans' capacity to take up CO2 is greater than previously thought.
While this may soak up some of the CO2 that would otherwise warm the atmosphere, the flipside is that the new findings give further evidence that human activities are rapidly changing the chemistry of the deep oceans....
The scientist who first coined the phrase “ocean acidification”, Ken Caldeira, at the Carnegie Institution, California, US, says the extent to which the rising boundary will affect deep-sea corals and shelled organisms remains uncertain. “But when human activities start impacting remote parts of planet, it's a wake-up call that we are interfering in our planet’s functioning on a very large scale,” he says. - NewScientist