Forgive my ignorance, but how would ocean afforestation lead to continuous CO2 sequestration unless the plants were harvested and buried or turned into biochar or something similar? I just did an interview with Ricardo Letelier of Oregon State and he warned that any attempts to increase biological productivity by adding nutrients to the ocean won't necessarily lead to increase sequestration, because what's really key is the proportion by which you increase the export productivity of a system. (i.e. the amount of carbon being siphoned off the system as dead organisms sifting to the ocean floor)
In other words how does this avoid the pitfalls, already rather well documented, of iron fertilization? On Oct 21, 2:11 pm, [email protected] wrote: > Johnnie - You are suggesting ocean afforestation with increased CO2 > concentration for a faster growth rate. The ocean afforestation is a good > idea, but the CO2 Enhancement would be nutrient limited or mining nutrients. > Plus, you are expending a lot of energy to move CO2 when the CO2 will come to > you in the air. Extra CO2 is not useful without matching amounts of other > nutrients. > > > > > > > > Ocean afforestation is similar to terrestrial afforestation. Terrestrial > rainforests generally have thin nutrient-poor topsoil. The nutrients come > from rapidly decaying biomass. The rainforest even manufactures its own rain > (local water recycling). Most of the ocean is a nutrient desert. Setting up > an ecosystem that rapidly recycles the nutrients (not mining the nutrients, > recycling the nutrients) allows ocean afforestation with a forest of > sargassum (or kelp, or microalgae, or ...). > > > > > > > > Rapid decomposition of aquatic plants into the nutrients needed to grow more > aquatic plants is accomplished by bacteria. When there is an excess of > aquatic plants due to an excess of nutrients, aerobic bacteria will deplete > all the dissolved oxygen while creating nutrients, water, and carbon > dioxide. The aerobic bacteria cause ocean dead zones. When there is no > oxygen available, anaerobic bacteria will continue the decomposition creating > nutrients, water, methane, and carbon dioxide. Because the carbon dioxide > will dissolves about ten times (by moles or volume) more than methane, we can > harness the anaerobic bacteria to produce pure methane (renewable natural > gas), pure carbon dioxide for sequestration, nutrients for ocean > afforestation, and harvest a little food on the side. > > > > > > > > None of this needs new science. We only help nature do what it normally > does a little faster. We have plenty of research on gas production from > anaerobic digestion, aquatic plant growth rates, fish farming, etc. The > result is a process that mimics nature. Every living plant and creature is > allowed to function naturally with relatively little change of their natural > environment. > > > > > > > > Applying engineering to the existing research suggests: > > > > 1) We start with an ocean reforestation project on 100 million hectare of > the North Pacific Gyre's plastic trash. We remove the trash before starting > the PODenergy process because autonomous aquatic plant harvesting can use the > same equipment as autonomous plastic harvesting. > > > > 2) 100 million hectare will produce 22 quads a year of methane worth $90 > billion a year at today's prices for natural gas (not even considering the > carbon credits premium for renewable natural gas). > > > > 3) At the same time, incidental to the methane production, we could > harvest less than 2% of the fish that accompany this ocean > reforestation. That would be a trillion kg per year or 140 kg of fish per > person per year for 7 billion people. > > > > 4) At the same time, incidental to the methane and fish production, we > could sequester the 850 million tonnes of liquid carbon dioxide produced. > > > > > > > > Of course we can start with smaller lake and coastal project harvesting > nuisance aquatic plants. But it is nice to know the PODenergy ecosystem is > sustainable at very large scales. More details are available at > www.PODenergy.net. > > > > > > Mark E. Capron, PE > Oxnard, Californiawww.PODenergy.net > > > > -------- Original Message -------- > Subject: [geo] .... > > read more » --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
