Iron particles sprinkled in the ocean seem to get rid of carbon dioxide. But German study has come under attack from many experts
German researchers on Wednesday said they had evidence that sowing the ocean with iron particles sucks up and stores carbon dioxide (CO{-2}), preventing the gas from stoking dangerous climate change.
But their work, touching on a fiercely controversial issue called geo-engineering, came under attack from other scientists and environmentalists.
These said a far bigger question — whether such schemes could damage the marine biosphere — remained unanswered.
Published in the science journal Nature, the paper is one of the biggest and most detailed probes into ocean fertilisation.
Ocean fertilisation is banned under international law although scientific research into it is permitted.
Its goal is to take CO{-2}from the atmosphere and store it in the deep sea so that it no longer adds to the greenhouse effect.
This would be done by scattering the ocean surface with iron dust, a nutrient for microscope marine vegetation called phytoplankton. As the plants gorge on the iron, they also suck up atmospheric CO{-2}thanks to natural photosynthesis.
In the next step, the phytoplankton die and sink to the deep ocean floor — taking with them the CO{-2}, which would lie in the sediment, possibly for centuries.
Critics, though, say geo-engineering schemes are riddled with unknowns, both in cost effectiveness and risks for the environment.
Among the critics was Professor John Shepherd, who chaired a landmark report in 2009 by Britain's Royal Society.
It concluded that ocean fertilisation would not suck up that much CO{-2}and could be harmful to the marine biosphere.
Á Canada-based environmental organisation campaigning against geo-engineering, said the study "only focuses on a few narrow aspects and disregards or ignores others."
"The intended purpose of ocean fertilisation is to significantly disrupt marine ecosystems through drastic changes on phytoplankton, which is the base of the marine food web, so the effects would be unpredictable," it said.AFP
Source: The Hindu,25th July 2012