My point is that the 25% figure is the most generous assessment that can be made at present. A more realistic one would assume far less than 100% coverage of the HNLC areas and a much higher total GHG emissions. In that more likely scenario, OIF provides for 200MtC removal and total emissions are 10GtC in which case OIF is responsible for offsetting 4% of atmospheric gain and 2% of total emissions. To get to 200MtC removal will be an enormous task. By 2050, if emissions have doubled, OIF would remove only 2% of atmospheric gain, a measureable, but minor mitigation technology.
----- Original Message ----- From: "Dan Whaley" <[email protected]> To: "Alvia Gaskill" <[email protected]> Sent: Tuesday, December 16, 2008 10:35 AM Subject: Re: Ocean Fertilization, an Incomplete Answer with Uncertain Long Term Implications Say Aussies Alvia, I find this comment very strange: "OIF gets a lot of attention for a technology that will never remove more than 25% of CO2 added to the atmosphere." Can you explain your thinking? I assume you are by now tired of looking at McKinsey curves and hearing speaker after speaker refer to the need to take a portfolio approach, etc. etc. 25% of annual emissions is quite a large number. We should be so lucky. This would be larger than any single constituent of the global McKinsey cost of abatement curve. Nearly three times worldwide deployment of CCS. Oliver, I am quite intrigued by your comments ... Can you refer me to the specific paper(s) pls? Dan D On Dec 15, 12:32 pm, "Alvia Gaskill" <[email protected]> wrote: > Regarding the "absorption limit" for OIF, what should be the baseline > against which the effectiveness of OIF is evaluated? Should it be the > total of human CO2 emissions, the total of all human GHG emissions or > should it be the amount of CO2 that is added to the atmospheric inventory > annually? > > If the maximum quantity that can be captured by OIF enhanced plankton is > constant, wouldn't the percent effectiveness decrease as human emissions > increase as they likely will and also, as the natural sinks become less > effective? > > I participated in a discussion recently regarding this issue, although not > about OIF specifically. The decision was to base the effectiveness on the > amount of CO2 added to the air and not the total emissions, assuming that > about half the emissions wind up in the air. This also relates to how > carbon credits from OIF would be calculated. Do the credits apply to the > emissions or to the amount added to the air? > > Example calculations to illustrate these points: > > 1GtC from OIF/4GtC added to air each year in 2008 = 25% > > 1GtC/8GtC emitted by humans in 2008 = 13% > > 1GtC/6.66GtC as CO2 emitted by humans in 2008 = 15% > > 1GtC/16GtC emitted by humans in 2050 (arbitrary emissions and date, not > any specific scenario) = 6% > > OIF gets a lot of attention for a technology that will never remove more > than 25% of CO2 added to the atmosphere. > > ----- Original Message ----- > From: Ken Caldeira > To: [email protected] > Cc: [email protected] > Sent: Monday, December 15, 2008 1:00 PM > Subject: Re: [geo] Ocean Fertilization, an Incomplete Answer with > Uncertain Long Term Implications Say Aussies > > And while we are thinking deeply about this potential threat, we will > continue to strip mine the ocean of edible fish. > > I am not a big fan of ocean fertilization, but I do not think that anybody > has come up with any plausible damage from a well-managed ocean > fertilization program that is of the same order-of-magnitude as what we > are already routinely doing to the ocean with overfishing. > > I am even less clear on what the "irreversible risk" is supposed to be > from a well-managed ocean fertilization program. Assuming that you monitor > for anticipated risks, what could happen that would not be likely to > reverse itself after fertilization ceases? > > [ By well-managed, I mean that endemic species abundances and oxygen > contents and things like that are being monitored, so that you do not > induce extinctions ... which are irreversible. ] > > [ This is not an excuse to induce more damage, but just a comment to note > that attention to various potential risks are often incommensurate with > the amount of actual risk incurred. ] > > On Mon, Dec 15, 2008 at 5:29 AM, Alvia Gaskill <[email protected]> wrote: > > http://www.alertnet.org/thenews/newsdesk/SP39844.htm > > RPT-FEATURE-Scientists urge caution in ocean-CO2 capture schemes 15 Dec > 2008 13:04:25 GMT > Source: Reuters > (Repeats story that moved at 0000 GMT) > > By David Fogarty, Climate Change Correspondent, Asia > > SINGAPORE, Dec 15 (Reuters) - To some entrepreneurs, the wild and icy seas > between Australia and Antarctica could become a money spinner by > engineering nature to soak up carbon dioxide and then selling carbon > credits worth millions of dollars. > > To some scientists and many nations, though, the concept of using nature > to mop up mankind's excess CO2 to fight global warming is fraught with > risk and uncertainty. > > An analysis by a leading Australian research body has urged caution and > says more research is crucial before commercial ventures are allowed to > fertilise oceans on a large scale and over many years to capture CO2. > > "I don't think the scientific community has even sat down and made a list > of the things we need to check before we feel comfortable that this would > be a low-risk endeavour," said one of the Australian report's authors, Tom > Trull. > > "We never even designed measurement programmes to look at ecological > change and the risks," said Trull, Ocean Control of Carbon Dioxide > programme leader at the Antarctic Climate and Ecosystems Cooperative > Research Centre (ACE CRC) in Hobart. > > Scientists say sprinkling the ocean surface with trace amounts of iron or > releasing other nutrients over many thousands of square kilometres > promotes blooms of tiny phytoplankton, which soak up carbon dioxide in the > marine plants. When the phytoplankton die, they drift to the ocean depths, > along with the carbon locked inside their cells where it is potentially > stored for decades or centuries in sediments on the ocean floor. > > Firms eyeing this natural carbon sink hope to commercialise it to yield > carbon credits to help industries offset their emissions. > > The problem is no one knows exactly how much carbon can be captured and > stored in this way, for how long, or the risks to ocean ecosystems from > such large-scale geo-engineering. > > Some scientists fear such schemes could change species composition in the > oceans, increase acidity or cause oxygen depletion in some areas, even > promote the release of another powerful greenhouse gas, nitrous oxide. > > BLOOMING > > "Ocean fertilisation may cause changes in marine ecosystem structure and > biodiversity, and may have other undesirable effects," says the ACE CRC > position analysis on ocean fertilisation science and policy, soon to be > publicly released. > > "While controlled iron fertilisation experiments have shown an increase in > phytoplankton growth, and a temporary increase in drawdown of atmospheric > CO2, it is uncertain whether this would increase carbon transfer into the > deep ocean over the longer-term," it says. > > It also says the potential for negative impacts is expected to increase > with the scale and duration of fertilisation. There are doubts that any > damaging effects could be detected in time. > > "It is very important to recognise that if deleterious effects increase > with scale and duration of fertilization, detection of these cumulative > effects may not be possible until the damage is already done," said John > Cullen, professor of oceanography at Dalhousie University at Nova Scotia > in Canada. > > "It is extremely important to look at the ecological risks of this kind of > activity," he said. > > Oceans soak up vast amounts of CO2 emitted by nature or through burning of > fossil fuels and deforestation and the Southern Ocean plays the greatest > role of all the oceans. > > But much of the Southern Ocean is depleted of iron and experiments have > shown even small amounts of the nutrient can trigger phytoplankton blooms > that can last for up to two months. > > Companies such as California-based Climos and Australia's Ocean > Nourishment Corp are planning small-scale experiments to test their ocean > carbon capture and sequestration projects. > > Ocean Nourishment uses ammonia and urea, delivered via a marine pipeline > to a region deficient in nitrogen, to boost phytoplankton growth and boost > fish stocks. Climos uses iron and plans experiments in the Southern Ocean > in 2010. > > "Iron fertilization is no silver bullet for climate change -- which > underscores the severity of the problem we have, and the urgency for > immediate emissions reductions worldwide," Climos founder and CEO Dan > Whaley told Reuters in an email interview. > > But he said it was premature to judge iron fertilisation as dangerous. > > "Phytoplankton are nature's way of sequestering CO2 to the deep ocean, > where nearly 90 percent of earth's carbon lies. Further, most everything > we put up in the air is going to the deep ocean eventually. The only > question is how long it takes," he said. (For separate Q&A with Climos, > click on [ID:nSP376631]) > > Many nations, though, remain cautious and member states of two treaties > that govern dumping of wastes at sea passed a non-binding resolution in > October calling for ocean fertilisation operations to be allowed only for > research. > > Parties to the London Convention and related London Protocol, part of the > International Maritime Organisation, signed the resolution that said > member states were urged to use "utmost caution" to evaluate research > proposals to ensure protection of marine life. > > ABSORPTION LIMIT > > Trull, who participated in the first ocean fertilisation experiment in > 1999, one of a dozen since conducted globally, said commercial ventures > would need to operate over huge areas of ocean for many years. > > The ACE CRC report also says ocean fertilisation just using iron would > likely hit an absorption limit of about 1 billion tonnes of carbon (3.7 > billion tonnes of CO2) annually, or about 15 percent of mankind's total > carbon emissions. > > "That really puts the risk in context. We're talking about altering > ecosystems of planetary scale for a benefit that won't actually relieve us > from dealing with all the other issues, such as conservation or > alternative energy generation." > > Cullen of Dalhousie University said studies suggested that to sequester > large amounts of carbon would require fertilisation of most of the > Southern Ocean for long periods of time. > > "The question is can we assess those large-scale and long-term effects on > the basis of experiments 100 by 200 km (60 by 120 miles) in size. I have > not seen evidence it can be done." > > (Editing by Megan Goldin) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. 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