The reason you've never heard of Ocean Fertilization

A sordid tale of environmental organizations going balls-to-the-wall to stop one of our most promising tools against climate change

Quico Toro

Mar 10, 2025

John Martin would be appalled at how this all played out

Tell someone you meet at a cocktail party that it’s possible to suck billions of tons of carbon from the atmosphere by sprinkling minerals into the ocean and, well, eyebrows are prone to rise. You can sense your fellow guest thinking to themselves “oh great, I’m getting buttonholed by some crank.”

It’s a problem for Ocean Fertilization, no two ways around it. The deeper you get into the research, the crankier you sound: “Oh so now this is gonna solve not just global warming but ocean acidification too, and replenish fish stocks and bring back the whales? Next he’s gonna tell it’s going to clean my garage …”

Marine Carbon Dioxide Removal labors under the paradoxical curse of sounding too good to be true. This makes people uncomfortable. People sense there has to be a catch. They intuit there must be big risks.

If their intuitions were off, they figure, we’d be hearing about mCDR all the time, right? Something doesn’t pass the smell test here.

“So if this idea is so great,” they might ask, “how come we never hear about it?”

It sounds like a simple, reasonable question.

It’s a trap.

Because if you tell a normie that the reason they haven’t heard of Ocean Fertilization is that a cabal of powerful environmental organizations successfully campaigned to kill one of our most promising climate solutions, you come across as a straight-up conspiracy-theorist nutter.

Except, well, it’s true. That’s just a straightforward recounting of what happened.

Let’s backtrack to tell the whole sordid story from the start.

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For much of the last century, oceanographers faced a mystery. They saw that vast stretches of ocean held little if any marine life: Fish, crustaceans, whales, even plankton were either missing or present in far lower concentrations than you would expect. But the water had all the nutrients life needed to thrive: Plenty of nitrates, lots of phosphorus, enough iron, everything. So where was everyone?

It took a stroke of genius by a lone oceanographer, John Martin of the Moss Landing Marine Lab, to find the answer.

Martin had long suspected that the problem was iron: far from land (and thus, from iron-rich dust) the ocean didn’t have any sources of iron. But then, water samples from marine deserts didn’t show that. Martin reasoned that the research boats themselves were contaminating the samples. Tiny bits of material from the ships’ steel hulls were making their way into their samples, that’s why they showed trace quantities of iron in the water no matter how far they were from land.

We’re talking truly miniscule concentrations —these ships weren’t rust buckets— but even a tiny bit of contamination was enough to mess up the samples.

To prove his point, Martin designed an elaborate new protocol to gather ocean water samples without contaminating them. The tests carried out following Martin’s protocol showed that the water in ocean deserts often contained no iron at all. This, Martin argued, was the reason nothing was growing there: Phytoplankton do fine in low-iron conditions, but they don’t survive where there’s no iron at all. Iron, he suggested, was the limiting factor for phytoplankton growth. And since everything in the ocean eats either phytoplankton or something that ate phytoplankton or something that ate something that ate phytoplankton (and so on), the absence of iron would explain why life in general couldn’t thrive over vast stretches of the ocean.

It’s fair to say that Martin’s hypothesis was badly received at first. It seemed borderline childish — how could this one mineral account for so much? So Martin pushed for a series of experiments to test his idea, going out to areas with a lot of nutrients in the water but little marine life to see what would happen if you dissolved a tiny bit of iron in them.

In one of those heartbreaking twists of fate, Martin himself died just before the first of the experiments was carried out. He never got to see his hypothesis first confirmed, and then replicated many times over. A total of 13 scientific trials were conducted in various oceans to test his idea in the 1990s and 2000s, and all of them found it was freakishly easy to set off large phytoplankton blooms by adding tiny amounts of iron to the water.

In a now famous 1988 speech to the Woods Hole Oceanographic Institute, Martin had told his colleagues “give me half a tanker of Iron and I will give you an ice age.” It sounds crazy, but it was a provocation with a point. Phytoplankton only needs tiny amounts of iron to do its thing. And he was right about the ice age bit too. In the decades since Martin’s speech, paleoclimatologists have found good evidence in ice core and ocean sediment studies to show iron deposition over the ocean really did increase ahead of each ice age.

As more and more experiments showed iron’s prodigious ability to fertilize plankton blooms, some scientists began to draw the obvious inference: Do this on a wide enough scale, and you could soak up enough carbon to put a dent in global warming.

At this, the big environmental NGOs got very uncomfortable.

It all came to a head over the ill-starred LOHAFEX experiment: a German-Indian research collaboration that turned toxic when the World Wildlife Fund (WWF), Greenpeace and others mobilized to put together a full-court press to get the German government to stop the trial and turn public opinion against the research.

The campaigners lost the battle but won the war: The two governments went ahead with the trial despite the protests — and no, none of the horrible things protesters had warned might happen did happen. Mostly, a huge phytoplankton bloom ensued, making lots of lovely food for all the fishies in the Indian Ocean. But public opinion had been turned against Ocean Fertilization: scientists came to see it would be a huge and draining fight to get new trials approved, so they stopped proposing them.

How was this achieved? Through a torrent of scaremongering about “tinkering with nature” and the threat of geo-engineering, with organizations like the World Wildlife Fund going into overdrive to raise concerns about the looming threat to the planet. In one gloriously contradictory piece of messaging, at one point the WWF came out against large-scale ocean fertilization research on the basis of the fact that we don’t know enough about what Ocean Fertilization will do...which, duh, that’s why you do research!!

It amounted to a kind of globalized NIMBYism, with organizations mobilizing to stop research anywhere in their earth-sized backyard. At around this same time, they were going all out against genetically-modified crops, warning about the dire dangers of frankenfoods—it was a strange era of anti-science backlash from the left, really.

But whereas GMO crops had the giant, cash-flush and politically powerful agro-industrial behemoth to fight for them, Ocean Fertilization had nobody but a few dozen nerdy oceanographers to speak up on its behalf.

This is why when you go to the store, every other product you find has GMOs in it and you don’t really worry about them anymore, but no big Ocean Fertilization trials have taken place in over a decade now.

Look, I obviously think the activists who torpedoed this line of research had it badly wrong, but I sort of get where they were coming from. As they saw it, they were involved in an all-consuming political struggle to convince people of the need to stop emitting CO2, and anything that might draw focus away from that, they were immediately against.

This was the time of braindead Republicans bringing snowballs into the floor of the U.S. Senate to “prove” climate change was a hoax. It really was an uphill struggle just to get it through to the public that climate change was real and greenhouse gas emissions caused it.

When you’re in the middle of a knock-down-drag-out political fight like that, with a well-resourced opponent coming up with new bullshit ways to try to confuse the issue every other day, well, you get paranoid. Pretty soon anything outside the party line starts to look suspicious; a distraction from the one thing you’re trying to convince people is important.

That feeling congealed around the so-called “moral hazard” argument against things like Ocean Fertilization: The gnawing worry that this was a trick, a fossil fuel industry diversionary tactic at best, just an excuse to give themselves political cover to keep polluting.

Moral hazard remains, to this day, the most commonly articulated argument against Ocean Fertilization. It is the argument that will definitely come up, every single time. In a 2009 context, I can sort of get how that made sense. “Focus, people!” was the green message of the day. How’s that worked out?

Back then, the world was emitting the equivalent of 44.8 billion tons of CO2. Then we spent a decade and a half being very careful to keep the focus on emissions reductions, and where did that leave us? Emitting 53 billion tons of CO2 worth of gunk. Since the LOHAFEX fiasco, global emissions grew every single year, with the sole exception of pandemic-hit 2020.

People in the green movement will really be like “you believe in ocean fertilization? That pales in effectiveness to my strategy, emissions reductions” and then not reduce emissions.

Moral hazard is a nonsense argument. It demands that we stop talking about things that could work so we can devote all our energy to a strategy that failed. It mounts its moral high horse to argue for non-solutions, blithely condemning generations of kids in developing countries to suffer the worst impacts of climate change and energy poverty. Rather than actually trying to solve the problem, it offers pretexts for inaction. A movement that shouts “Emergency!” at the top of its lungs all day and all night freaks the hell out whenever someone tries to behave in the sort of ways you behave in a real emergency.

The whole thing makes my stomach turn.

The reality is that carbon dioxide emissions are very likely to continue to grow faster in the developing world than they fall in the developed world.

In 2024, China built 94 large coal-fired power plants, 1 GW each. India and Indonesia are building gigawatt-scale coal plants right now too. Green politics in rich countries can’t change that underlying reality. What people in the first world can do, though, is help develop the technologies able to actually take some of that carbon out of the air before it buggers us all. It takes a particular kind of moral turpitude to think opposing Ocean Fertilization research makes the planet safer—it plainly doesn’t.

Of course, opponents are right that ocean fertilization does carry some risks, and its impact can’t be fully predicted ahead of time. But then, we face situations like this all the time.

Probably the most familiar instance of this is drug development. When you give a new drug to a patient for the first time, you of course can’t be sure exactly what it will do. If we insisted that you can’t give a new drug to a patient until all the risks are known, we’d make it impossible to discover new drugs. That would be absurd, so of course we don’t do that.

What we do instead is test new drugs following a well-defined protocol to gauge risk and effectiveness. We do a small trial first, we assess its safety and effectiveness. If it goes well, we do a larger trial, then we assess it again, and we keep doing that at successively larger scales until we’re sure the drug is safe and it works: then we offer it to the public.

New drug development protocols are a proven means of going from “hmmm, I think this might work, but I don’t know if it’s safe yet” to either “hey! this is safe and it really does work!” or “bummer, that one isn’t safe” or “bummer, that one didn’t work.”

Interpreting the precautionary principle to mean you can’t act until you have perfect information is NIMBYism posing as responsible caution. Citing uncertainty over the safety of a technique as a reason not to do the research able to establish the safety of that same technique is political prejudice masquerading as scientific circumspection.

Needless to say, by the time I’ve gotten through the whole of this rant the poor sap at the cocktail party who had the misfortune to ask me what I work on is thoroughly regretting his decision not to stay in bed with Netflix that night.

I almost feel bad for them. But then, I think of John Martin spinning in his early grave and I feel justified all over again.

https://www.onepercentbrighter.com/p/the-reason-youve-never-heard-of-ocean

also:

https://www.whoi.edu/know-your-ocean/ocean-topics/climate-weather/ocean-based-climate-solutions/iron-fertilization/

https://interestingengineering.com/science/fertilizing-the-oceans-with-iron-could-help-remove-a-gigaton-of-carbon-dioxide-per-year

https://phys.org/news/2024-09-case-adding-iron-ocean-carbon.html

(http://www.autoadmit.com/thread.php?thread_id=5694938&forum_id=2:#48752646)