Ocean fertilisation is a proposed form of geo-engineering that involves the introduction of iron particles to the upper ocean to stimulate a phytoplankton bloom.
In theory, the phytoplankton will then absorb CO2 before dying and sinking to the bottom of the ocean where the carbon will be sequestered.
An experiment in early 2009 in the Southern Ocean dampened hopes for widespread uptake of the technology after crustacean zooplankton fed on the bloom before it died and reintroduced the extracted CO2 into the atmosphere.
However, some scientists maintain that ocean fertilisation could prove a cost effective means of reducing concentrations of CO2 in the atmosphere. Environmental groups counter that large scale ocean fertilisation projects could have unexpected consequences on maritime food chains.
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