Connecting Carbon Capture with Oceanic Biomass Production

• Published in: Nature Precedings
• Main Author: Chen Wang
• Format: Manuscript
• Language: unknown
• Published: 2010
• Subjects: Chemistry; Ecology; Earth & Environment; Ocean acidification
• Online Access: http://precedings.nature.com/documents/5161/version/1; https://doi.org/10.1038/npre.2010.5161.1

The climate change believed by anthropogenic emission is not isolated but tightly coupled with other issues including biodiversity loss and ocean acidification etc., and in order to prevent the potential serious impacts, both political and technological methods are being tried for greenhouse mitigation. Dimming the income sunlight by some “geoengineering” approaches currently seem ruinously expensive and technically difficult, and would not prevent the increase of greenhouse gases (GHGs) in atmosphere and ocean acidification, so capturing carbon to reduce the environmental concentration of carbon dioxide (CO2) and promoting renewable energy development for the reduction of using fossil fuels are very necessary. Biofuels derived from natural and agricultural biomass could be deployed for power production and existing transportation needs. The current economics are more favorable for conversion of edible biomass into biofuels, which could spend plenty of freshwater and farmlands, compete with food supply, and create a “carbon debt” with local ecosystem destruction by deforestation to expand biofuel-crop production. So it is vital to develop processes for converting non-edible feedstock such as lignocellulose and microalgae into biofuels.
 Compared with lignocellulose, microalgae have higher growth rates, don’t need plenteous freshwater for irrigating, and can grow in the conditions that are not favorable for terrestrial biomass growth. The current limitation of microalgal biofuels is the microalgae cultivation cost, and to compensate the high cost of microalgal biofuels, three suggestions are propounded here. (i) Using ships as the platforms of cultivating microalgae, producing biofuels, and transporting feedstock and products on a large scale on subtropical oligotrophic oceans, where the ocean’s least productive waters are formed with compared peaceful surface condition and poor marine communities. (ii) Operating different kinds of oceanic biomass productions for high-value products to compensate the cost of microalgal biofuels. Different kinds of microalgae and macroalgae (seaweeds) could be cultivated for biofuels, chemicals, healthy food, and feed for breeding economic marine species to satisfy the accelerating demands for seafood supply and simultaneously mitigate the fast decline of wild stocks. (iii) Constituting financial subsidies to make CO2 as the feedstock of microalgae cultivation for free, and exact quantifying the carbon captured in biomass products and the CO2 reduction that these products would provide by displacing natural and nonrenewable carbon resources, to take part in the international carbon-credit trading markets and sell the offsets. In a word, this article mainly talks about trying to find a way that connect CO2 capture with renewable energy development, and partially combat against deforestation, loss of biodiversity, shortage of food, and decline of marine lives etc., if possible.