The volcano Eyjafallajökull erupts in Iceland in 2010. Hope that iron in the ash plume would fertilize the ocean and lead to a carbon-dioxide-absorbing phytoplankton bloom were overly optimistic, scientists report.
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LONDON – Plankton, tiny marine organisms, are a good way of cleansing the atmosphere of one of the main greenhouse gases, carbon dioxide. To do this they need dissolved iron to help them to grow, and if they lack iron then they cannot do much to reduce CO2 levels.
So the eruption in 2010 of an Icelandic volcano gave scientists a perfect opportunity to see how much the cataclysm helped the plankton by showering them with unexpected clouds of iron.
Their verdict, published in the journal Geophysical Research Letters – the volcano certainly helped, but not for long enough to make much difference.
This is a blow to some supporters of geo-engineering, who have suggested that one way to tackle climate change is large-scale seeding of the oceans with iron to stimulate plankton to absorb more carbon dioxide.
The volcano's impact was assessed by a team led by scientists from the UK's National Oceanography Centre, Southampton, who were on a shipboard research expedition in the area at the time.
Air travel to a standstill
The April 2010 eruption of the volcano Eyjafjallajökull hurled clouds of ash several kilometers into the atmosphere, bringing air travel to a standstill across Europe and, in a less noticeable effect, seeding the seas south of Iceland with ash.
In many parts of the ocean the productivity of phytoplankton – microscopic plants at the base of the marine food chain – is limited by the availability of dissolved iron.
In 2007 the team had shown that, after a large spring bloom, phytoplankton in the Iceland Basin failed to grow much because it lacked iron. The scientists wanted to see whether the ash from Eyjafjallajökull supplied enough iron to sustain the spring blooms for longer than usual.
The team found that the five-week eruption supplied enough dissolved iron to increase the number of phytoplankton cells within a region of the North Atlantic stretching across 570,000 square kilometers – or 220,000 square miles, about the size of France.
Short-lived effect
But the effect was short-lived as the extra iron resulted in the rapid removal of biological nitrate, depriving the phytoplankton of nitrogen they also needed.
The team – from Southampton, the University of Cape Town and the Norwegian Institute for Air Research – conducted three research voyages in 2010 investigating ocean productivity in the area affected by ash from Eyjafjallajökull.
They took samples of ash and dust in the atmosphere, and of nutrients in the ocean, and also measured the activity of the phytoplankton.
The north Atlantic Ocean is globally important, as it is a sink for atmospheric carbon dioxide, said Eric Achterberg, chief scientist for the research cruise and lead author of the study.
"A limit to the availability of iron in this region means that the ocean is less efficient in its uptake of atmospheric carbon dioxide," he said.
"The additional removal of carbon by the ash-stimulated phytoplankton was therefore only 15 percent to 20 percent higher than in other years, making for a significant but short-lived change to the biogeochemistry of the Iceland Basin."
The National Oceanography Centre develops technology for coastal and deep ocean research. It is based in Southampton and Liverpool.
This article originally appeared at The Daily Climate, the climate change news source published by Environmental Health Sciences, a nonprofit media company.
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7 Comments
Add CommentAs a person who traded such 'ocean sequestration carbon credits,' my natural skepticism kept nagging at me all the while; questioning whether we really were indeed doing the right thing through iron seeding, or simply entertaining ourselves with busy work, formulated under a Penultimate Set Logic Fallacy. "But the effect was short-lived as the extra iron resulted in the rapid removal of biological nitrate, depriving the phytoplankton of nitrogen they also needed." This shames me. Not in that I held enough information to have known this failure element might occur of course, but rather in that I know that a Penultimate Set Fallacy - the presumption that we hold enough information in a domain to make a pre-prejudiced conclusion (or hold the 'next to last' piece of information knowable) - that a Penultimate Set Fallacy was indeed likely in this subject, and sadly that I was forced by economic sophistry to go along with it the Fallacy. But one cannot speak up when the emperor has a whole new wardrobe.
Reply | Report Abuse | Link to thisWe all need to step back into the box of humility. Back into the box of true skepticism. I believe that there exists a cause and a solution. We need less boasting, more ethics and more science on subjects like this.
I think we will eventually do the right thing however.
- TES
If anyone wants to read more about ocean sequestration of carbon here is a link to one site discussing it.
Reply | Report Abuse | Link to thishttps://www.whoi.edu/oceanus/viewArticle.do?id=34167
They don't seem to be sure what they think of the idea yet.
This could be the kind of thing you are talking about. Someone posted this video on one of the other comment boards. I can't confirm they actually did this, but it is told as truth.
Reply | Report Abuse | Link to thisThe video talks about killing elephants because they thought desertification was due to overgrazing. They claim to have killed 40,000 elephants and then desertification only got worse. "Sorry about that elephants. We meant well."
http://www.fastcoexist.com/1681518/this-man-shot-40000-elephants-before-he-figured-out-that-herds-of-cows-can-save-the-planet
This is not that surprising to scientists. The North Atlantic is NOT iron-limited, unlike the Southern Ocean, which is why most such experiments focus on the Southern Ocean.
Reply | Report Abuse | Link to this*not THAT iron limited, compared to the Southern Ocean
Reply | Report Abuse | Link to thisTo The Ethical Skeptic - Yes you are probably right; we will eventually do the right thing. I'm afraid that we, the people of the world, will act as Winston Churchill said about Americans in particular: "Americans always do the right thing... after they have exhausted every other possibility." If we wait that long, and charge down the path of climate engineering, instead of correcting the obvious problem (i.e., too much use of fossil fuels) we will doom our children and grandchildren to an uncomfortable, dangerous and less prosperous future.
Reply | Report Abuse | Link to thisBiomass pyrolysis produces gas and biochar, which is used as a soil amendment. The charcoal therefor sequesters carbon from CO2 and as such is the only viable method of geoengineering.
Reply | Report Abuse | Link to thisSee www.eprida.com or 'International Biochar Initiative'.