Salvando el planeta con biotecnología apropiada: 4. Cultivo de cocolitóforos e implementación

Abstract

Cultivating coccolithophore algae for carbon sequestration is discussed. Coccolithophores have been major calcium carbonate producers in the world’s oceans for about 250 million years. Today, they account for about a third of the total marine CaCO3 production by coating their single cells externally with plates of microcrystalline CaCO3. The possibility that these algae could be used to trap atmospheric CO2 with existing technology has not been widely considered. There is scope for both high technology cultivation in bioreactors and low technology cultivation in terraced raceway ponds or lagoons on tropical coastal sites. The latter could produce a sludge of pure CaCO3 as a feedstock for cement production in place of the fossilised limestone currently used (cement production accounts for around 8% of industrial fossil CO2 emissions). On the high seas coccolithophores naturally produce extensive blooms, which emit the volatile gas dimethyl sulfide to the atmosphere, where it promotes formation of clouds that block solar radiation. The vision is for aquaculture nurseries onboard factory ships, cultivating both coccolithophores and bivalve molluscs, creating and maintaining blooms of coccolithophores in the oceanic high seas to sequester carbon from the atmosphere and generate cloud cover to cool the immediate environment.