OCEAN ALGAL AFFORESTATION (OAA) TO ADDRESS CLIMATE CHANGE ISSUES IN THE PACIFIC REGION

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1 Source: BoxNutt.com OCEAN ALGAL AFFORESTATION (OAA) TO ADDRESS CLIMATE CHANGE ISSUES IN THE PACIFIC REGION Antoine De Ramon N Yeurt 1, David P. Chynoweth 2, Mark E. Capron 3, Jim R. Stewart 4, and Mohammed A. Hassan 3 1 Pacific Centre for Environment & Sustainable Development, The University of the South Pacific, Suva, Fiji 2 Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL 32611, USA, 3 PODenergy, 2436 E. Thompson Blvd., Ventura, CA USA, 4 PODenergy, 1216 S. Westlake Ave., Los Angeles, CA 90006, USA,

2 Ocean Algal Afforestation (OAA) is a Negative Emission Technology utilizing the world s oceans to reduce atmospheric carbon dioxide concentrations through expanding natural populations of large seaweeds (macroalgae), which absorb carbon dioxide through photosynthesis like terrestrial forests. The marine algae are harvested to produce biomethane and biocarbon dioxide via anaerobic digestion; the biocarbon dioxide is sequestered. The plant nutrients remaining after digestion are recycled to expand the algal forest and increase fish populations, in a Integrated Multi-Trophic Aquaculture process. This amount of biomass could also increase sustainable fish production to potentially provide 200 kg/yr/person for 10 billion people. Additional benefits are reduction in ocean acidification, and increased ocean primary productivity and biodiversity.

3 Source: NASA Based on macro-algae forests covering 9% of the world s ocean surface, OAA has the potential to produce 12 billion tons per year of biomethane while storing 19 billion tons of CO 2 per year directly from biogas production, plus up to 34 billion tons per year from carbon capture of combustion exhausts. This is enough biomethane to replace all of today s needs in fossil fuel energy, while removing 53 billion tons of CO 2 per year from the atmosphere, restoring pre-industrial levels.

4 World Greenhouse Gases Emissions by Sector and Types (from ECOFYS, 2010) More than three-quarters of global GHGs is Carbon Dioxide

5 Capacity, readiness and cost of prospective Negative Emission Technologies or NETs (Adapted from McLaren, 2012)

6 McLaren (2012) estimated the global requirement for carbon dioxide removal at 1200 Gt of CO 2 /yr. (24 Gt/yr for 50 years). The OAA circle includes the following: OAA bio-ch 4 replacing fossil eliminates the 40 Gt/yr of unneeded fossil fuels (U.S. EIA projection of 600 quads by 2035). OAA sequestering the OAA bio-co 2 removes an additional 19 Gt of bio- CO2 = 59 Gt CO 2 /yr. Capturing and sequestering half the combustion exhaust CO 2 from power plants removes additional 17 Gt = 76 Gt CO 2 /yr removed. OAA in full operation could restore the climate in less than 30 years - but it would take 20 years to get in full operation for a total of 50 years to get back to 300 ppm.

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8 Simplified schematic of OAA Concept (from PODEnergy)

9 Source: University of Hawaii THE CURRENT PROBLEM FACING MANY PACIFIC ISLAND COUNTRIES: Nasese, Fiji Ulva prolifera Honolulu, Hawaii: Gracilaria salicornia TOO MUCH SEAWEEDS! Nasese, Fiji Gracilaria edulis

10 SOME POSSIBLE CAUSES FOR OVER-ABUNDANT SEAWEEDS? Rising seawater temperatures as a cause of climate change Pollution from sewage, industries, fishing fleet wastes Excessive inputs of nutrients into coastal waters: domestic effluents, animal husbandry, sediment runoffs from deforestation, fertilisers from agriculture Poor water circulation in lagoons due to changes in oceanic currents, blocking of natural passes, coastal infrastructure Likely an adaptation to all of the above conditions by opportunistic species

11 A POSSIBLE SOLUTION?? THE ANAEROBIC DIGESTION OF ALGAL BIOMASS

12 THE PRODUCTION OF BIOMETHANE BY ANAEROBIC DIGESTION C 6 H 10 O 5 + H 2 0 3CO 2 + 3CH 4 The three stages of anaerobic digestion involving three sets of specialized bacteria (Source: Encyclopedia of Alternative Energy

13 Low-cost anaerobic digesters could convert over-abundant seaweed biomass into biomethane and provide a sustainable source of biofuel for local communities. By the addition of seaweed cultivation, there can be a continuous supply of biomass and excess biofuel could be sold to generate additional income for communities. A 500 ha operation could in theory produce about 7,000 dry tons of algal biomass per year. This biomass could power continuous 800 kw electricity generation (worth about $1.5 million USD per year) plus 1,500 kw of useable heat. This renewable energy is equivalent to a GHG reduction of 2,000 metric tons of CO 2 per year, or about $60,000 USD annually via a Clean Development Mechanism (CDM). Residue sludge from the anaerobic digestion would have a high content of potassium (up to 13.49% dry weight for Gracilaria edulis), plus nitrates and other minerals. This residue could be washed, dried and crushed to be recycled to fertilize the seaweed farm, or sold as a low-cost land crop fertiliser.

14 Source: Wikipedia Source: Sarah Hemstock Plant biomass (Hawaii) Piggery waste (Tuvalu) LOW-COST ANAEROBIC DIGESTERS FOR PACIFIC COUNTRIES

15 Solomon Islands Kiuva, Fiji Gracilaria (Brazil)) Tuvalu SEAWEED CULTURE Kelp (China)

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17 EXISTING USE OF MARINE BIOMASS FERTILISER IN BEQA, FIJI (Seagrass Syringodium isoetifolium, and seaweed Sargassum polycystum) Used on tomato, yagona, watermelons. Better yield, no pests or diseases.

18 THANK YOU VERY MUCH! Vinaka! Further reading: N Yeurt, A.D.R., Chynoweth, D.P., Capron, M.E., Stewart, J.R., Hasan, M.A Negative Carbon via Ocean Afforestation. Process Safety and Environmental Protection 90: