Here is a new entry
on Iron Fertilization (Ocean Fertilization) which directly addresses some of the "controversy" over the subject. Interesting stuff.As I said in an earlier post
, this is the one carbon sequestration technology which seems slightly strange to me because it seems most promising yet hasn't moved much in a decade of research.
Also I've received a few letters, which I'll keep confidential for now, which indicate some strange goings-on in the field. I plan to dig into this more.
While many advocates of ocean iron fertilization see it as modern society's last best hope to slow global warming long enough to change our consumption patterns and energy systems, a number of critics have also arisen including some academics, deep greens
and proponents of competing technologies who cite a variety of concerns.
Critics: Large scale bloom stimulation has never been done before. We don’t know exactly how they will act. There could be unintended side-effects. We should not risk it.
Advocates: Mother Nature has been annually stimulating far larger blooms for millions of years with no observed ill effects. The precautionary principle
provides a legitimate brake on this technique once plankton populations are restored to their known levels in 1980. Up to that point, however, plankton revival is simply eco-healing and little different from remedially treating superfund sites
, oil spills
or contaminated mothers milk.
Not even trying to remedy these industrial impacts is far more irresponsible considering the known pace of increasing harm.
Critics: According to certain ocean iron fertilization trial reports, this approach may actually sequester very little carbon per bloom and thus require too many seeding voyages to be practical.
Advocates: The low sequestration estimates that emerged from some ocean trials are largely due to three factors.
Timing: none of the ocean trials had enough boat time to monitor their blooms for more than 27 days, and all their measurements are confined to those early weeks. Blooms generally last 60~90 days with the heaviest precipitation occurring during the last two months.
Scale: most trials used less than 1000 kg of iron and thus created small blooms that were quickly devoured by opportunistic zooplankton
and fish that swarmed into the seeded region. Academic conservatism: having an obviously limited data set and unique sequestration criteria (see Sequestration Definitions below), many peer-reviewed ocean researchers are understandably reluctant to project or speculate upon the results their experiments might have actually achieved during the full course of a bloom.
Nevertheless, some ocean trials did indeed report remarkable results. According to IronEx II reports, their thousand kilogram iron contribution to the equatorial Pacific generated a carbonaceous biomass
equivalent to one hundred full-grown redwoods
within the first two weeks. Researchers on Wegener Institute's 2004 Eifex experiment recorded carbon dioxide to iron fixation ratios of nearly 300,000 to 1.
Current estimates of the amount of iron required to restore all the lost plankton and sequester 3 gigatons
of CO2 range widely, from approximately two hundred thousand tons/year to over 4 million tons/year. Even in the latter worst case scenario, this only represents about 16 supertanker
loads of iron and a projected cost of less the €20 billion. Considering EU penalties for Kyoto non-compliance will reach €100/ton CO2e in 2010 and the annual value of the global carbon credit market is projected to exceed €1 trillion by 2012, even the most conservative estimate still portrays a very feasible and inexpensive strategy to offset half of all industrial emissions.
Critics: The climatic contributions of this technique would only be partial, stop gap measures. Growing plankton in the ocean can't solve the basic problem, which is on land in the economies, policies and mental habits of industrial societies.
Advocates: Agreed, simply replenishing plankton populations will not solve the entire problem, but it could improve our chances by 50%. Returning plankton to 1980 levels could sequester nearly 3 billion tons of CO2 and neutralize half of the world's industrial emissions right now.
Yes, the ultimate problem is on the supply side and requires a radical change in consumption and energy policies. While climate campaigners wage the long political battles for those reforms, many habitats and ecosystems
are being destroyed right now and many scientists fear a fatal tipping point is at hand. Plankton replenishment is not the final answer, but it would buy many, many creatures breathing room until the fight for needed political and economic reforms is finally won.
Critics: In ocean science, carbon is not considered removed from the system unless it settles to the ocean floor where it is truly sequestered for eons. Most of the organic and inorganic carbon that sinks beneath plankton blooms is dissolved and remineralized at great depths and will eventually be re-released to the atmosphere, negating the original effect.
Advocates: Ocean science does traditionally define "sequestration" in terms of sea floor sediment that is isolated from the atmosphere for millions of years. Modern climate scientists and Kyoto Protocol
policy makers, however, define sequestration in much shorter time frames and recognize trees and even grasslands as important carbon sinks
. Forest biomass
only sequesters carbon for decades, but carbon that sinks below the marine thermocline
(100~200 meters) is effectively removed from the atmosphere for hundreds or thousands of years, whether it is remineralized or not. Since deep ocean currents take so long to resurface, their carbon content is effectively "sequestered" by any terrestrial criterion in use today.
Good vs. Perfect
Critics: Plankton restoration is only a technical fix. The only sane, acceptable solution is more conservation, abandoning fossil fuels, and switching to clean, renewable energy.
Advocates: True, but by this logic you could say condoms, diaphragms, and birth control drugs are only technical fixes for the population problem; the only sane, acceptable solution is celibacy. While perfect solution proponents compete for the moral high ground, too many creatures are already dying to postpone doing what we can. We absolutely do need long-term changes in economics, governance, and consciousness to treat the chronic problem, but we are facing an acute crisis right now and can administer important first aid years before the battles for needed reforms are likely to be won.
Harmful Algal Blooms (HAB)
Critics: Some plankton species cause red tides
and other toxic phenomena. How do we know what kind of plankton will bloom in these events? What will prevent toxic species from poisoning lagoons
, tide pools
and other sensitive ecosystems along our coasts?
Advocates: Most species of phytoplankton are entirely harmless, and indeed beneficial. Red tides and other harmful algal blooms are largely coastal phenomena and primarily affect creatures that eat contaminated coastal shellfish. Iron stimulated plankton blooms only work in the deep oceans where iron deficiency is the problem. Most coastal waters are replete with iron and adding more has no effect. Since all phytoplankton blooms last only 90~120 days at most, in the open ocean fertilized patches of any species will dissipate long before reaching any land.
DMS (Dimethyl sulfide
Some species of plankton produce DMS, a portion of which enters the atmosphere where it is oxidized by hydroxy (HO), atomic chlorine (Cl)and(BrO) to form sulfate particles and ultimately clouds. During the Southern Ocean Iron Enrichment Experiments (SOFeX), DMS concentrations increased by a factor of four inside the fertilized patch. Widescale iron fertilization of the Southern Ocean would lead to substainal cooling well beyond increased CO2 uptake.
Deep water oxygen depletion
Critics: When organic bloom detritus sinks into the abyss, a significant fraction will be devoured by bacteria
, other microorganisms and deep sea animals which also consume oxygen. A large bloom could, therefore, render certain regions of the sea deep beneath it anoxic and threaten other benthic
Advocates: The largest plankton replenishment projects now being proposed are less than 10% the size of most natural wind-fed blooms. In the wake of major dust storms, many extremely vast natural blooms have been studied since the beginning of the 20th century and no such deep water dieoffs have ever been reported.
Critics: Depending upon the composition and timing of delivery, these iron infusions could preferentially favor certain species and alter surface ecosystems to unknown effect.
Advocates: CO2-induced surface water heating and rising carbonic acidity are already shifting population distributions for phytoplankton, zooplankton and many other creatures on a massive scale. If certain infusions or space/time coordinates do show asymmetrical selective impacts in certain regions, the effect is inherently constrained by the limited size and 90-day lifespan of each bloom. Only larger scale research will show if this is really a problem, what factors tilt the playing field, and/or whether this issue can be effectively addressedTechnorati: Carbon Sequestration, Global Warming, Coal, Wikipedia, Carbon Dioxide, Acidification, Plankton