You were polite not to mention it in your article, but this demonstrates again how absurd it was for people to get so freaked out by Planktos-style iron fertilization. Mother nature is already depositing 500 million tonnes of iron-rich dust every year, and clearly the implication is that the 500 million tonnes is a highly variable number (we could speculate that the number might fluctuate by, let's say, 100 million tonnes annually, depending on weather and wind conditions that year).

So the amount of iron rich dust going on the ocean may fluctuate wildly, by hundreds of millions of tonnes, and has certainly been doing so for the entire history of the planet. And oh yes, what about volcanic eruptions? A good-sized eruption can deposit how many more millions of tonnes? Or in some major eruptive periods, billions of tonnes?

In this case, there is only one possible conclusion: that the oceans are highly, and naturally, adapted to million-tonne variations, and that such variations are perfectly normal.

Yet when Planktos was planning to deposit a tiny fraction of that amount, 100 tons, in ways that could create clear and evident ecological benefit (increases in plankton growth equals increases in food for fish, whales, and seabirds) we see this huge opposition by scientists, talking about "potential side effects"?

Wow. That's as clear a case of scientific hysteria as I think we have seen in decades. Or maybe it's just a political maneuver disguised as science. Who knows.

The comment above is very right. I cannot understand the environmental groups and scientists for fighting so heavily against this methode. I am a member of greenpeace and local environmental group myself.

We are emitting 30 Billion tons of CO2 every year, doing the biggest experiment of mankind ever. But the attempts to run counter measures are treated with a magnification glas as big as the moon. As consultant for renewable energies and hydrogen technology development engineer I was looking forward, that this iron fertilization is being started sooner than later. Look at the development of the atmospheríc CO2 at the homepage of the Hawaii observarorium. It is not rising linear, it is speeding up. Congratulation to all persons, that delayed that technique for years, where absolutely no time is left to hesitate and fight scientific battles. There was a saying while I was doing my studies. Trying is of higher value than discussing. Which means, that you should try out things (on a scientific basis) and then start the discussion.
I wish all readers a blessed day
Gustav Boehm

Agreeing with the past two comments... I often have a hard time figuring out whether some of the vehement arguments against the iron trials are genuine or possibly well meaning strategy to keep the focus on addressing the root cause of the problem.

In either case I think it's very counterproductive because the amount of warming already baked into the situation even with best case scenario abatement action, would mean horrible environmental damage. How many species extinctions are worth it to adhere to an ideology of not trying to engineer the world?

Ocean iron fertilization and salt water ocean cloud enhancement would both seem to be quite reasonable ideas to experiment with. They are both merely duplicating natural processes. They both can easily start small scale and ramp up. They both have processes and dynamics that would make it highly unlikely for some unexpected threshold to be crossed that causes surprising unexpected disaster. They both have very short lived effect... unlike some other proposed geoengineering where effects can last years or decades after the process is discontinued.

Just to respond to another poster...

The reason that environmental groups are fighting iron fertilization so hard is simply about money and power. These groups want the problem to remain as severe and frightening as possible because that gives them the power to influence the political world in ways they never could in the past. And it increases their funding.

This is not to say that global warming isn't a severe problem -- I think it is -- but that the leaders of many green groups don't want an "easy" solution to come along, like iron fertilization, and "let people off the hook". They need a sense of hysteria and fear, not calm productive courage.

Personally the Planktos saga is a turning point for me. I have now officially lost hope in the environmental movement's ability to solve the problem. Power corrupts, and it has corrupted the environmental movement. They clearly don't want to solve the problem. They just want to scream and protest, and try to cram their political and social agenda down other people's throats. Even though I personally may agree with much of that agenda, I don't want to use bullshit tactics to win, because I know such a win will not last more than a decade before it falls apart.

I'm referring to the leadership of the environmental movement, by the way. The rank-and-file are still dedicated wonderful people. But they are being misled by their leadership.