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0 pointsgreglindahl7y ago0 comments

I thought that the biggest problem with the "seeding the ocean with iron" method of sequestration was not the "qualms of environmentalists" but that it turned out to sequester a lot less carbon than initially thought?

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philipkglass7y ago

Its sequestration efficacy is not well-established yet. I think that more experiments should be run to better quantify the effects. Some environmentalists oppose even additional research-scale trials. Some proponents of iron fertilization have internalized "some environmentalists oppose this, and efficacy still has large error bars" as "it probably works great but technophobic environmentalists want us to suffer deprivation instead."

btilly7y ago

More than that, articles like https://www.scientificamerican.com/article/fertilizing-ocean... indicate that the sequestration efficacy varies widely based on a variety of parameters that we do not yet know enough to control. In particular the type of diatom that blooms matters. A lot. And it isn't obvious how to get the one that you want.

Furthermore there is a question of what happens when deep ocean currents turn over the ocean. Does that CO2 come back out? We don't know. And that is the difference between solving the problem versus kicking it down the road for a few centuries.

But still environmentalists have moved to get all research into the topic shut down. Which I think is shortsighted at best. We have a big enough problem and few enough plausible options that I don't believe we should shut this one down.

marcosdumay7y ago

From the appearances, it has a lot of potential. Iron is extremely plentiful and has a very large impact on the small systems it was tried.

It is possible that inefficiencies take such a toil that it stops being viable, but it's not the opposition that make people think it can have a large impact.

philipkglass7y ago

There are reasons to think it may be effective. But I try to live by "The first principle is that you must not fool yourself – and you are the easiest person to fool." I want additional experiments to make findings robust. In particular, even if small fertilization inputs reliably lead to large biomass increases, we need to know how much of that added biomass sinks to the deep ocean before we know how effective it is at sequestration. That can mean trying to track carbon movement over complicated food webs.

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rsa40467y ago

I've lost track of the literature since the early 1990's, but from what I recall of the early IRONEX experiments the problem was that net sequestration was disappointing: despite significant increases in fixation, much of this new carbon is remineralized by heterotrophs prior to burial. However, I don't know what some of the more recent data have shown—

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philipkglass7y ago

btilly7y ago

marcosdumay7y ago

From the appearances, it has a lot of potential. Iron is extremely plentiful and has a very large impact on the small systems it was tried.

It is possible that inefficiencies take such a toil that it stops being viable, but it's not the opposition that make people think it can have a large impact.

philipkglass7y ago

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rsa40467y ago

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