Planktos is a for-profit firm selling carbon offsets that I wrote about here when I first heard about their delightful plan to pull carbon out of the atmosphere by dumping iron dust into the ocean. The idea is that plankton will eat it and thrive and suck carbon out of the water.
I was skeptical then, and according to my Ottawa Citizen colleague Kelly Patterson, smarter people than me are resisting, too:
[T]he American government urges other nations to scrutinize any such project, adding that “Planktos was not able to provide the EPA with any information … (on) the potential environmental impacts” of the plan.
In particular, the U.S. cites the possibility that the project would lead to toxic algae blooms, and that the decomposing plankton masses would release other greenhouse gases or choke off the oxygen supply in the deep ocean.
…That claim is disputed by Chris Field of the Carnegie Institution’s Department of Global Ecology, who says that the absorption of increasing amounts of carbon dioxide is the main cause of ocean acidification in the first place.
“It may be possible to store excess carbon in the ocean, but you’ll be acidifying the ocean when you do it, and causing a dramatic change in the the ocean’s ecology, with no known effects,” Mr. Field said.
Ken Caldeira, also of the Carnegie Institution, says “there’s no practical way to verify” that ocean seeding would sequester any additional carbon — and if it did, “it would exacerbate ocean acidification.”
A commenter at Grist Mill likens the idea of “seeding” plankton to adding a non-native species to a new environment to deal with some problem that exists there. “It remains unclear whether any intentional release of a non-native species has worked well,” caniscandida remarks dryly.
But Planktos insists the science is sound and is going ahead, possibly by using a flag-of-convenience ship if the American government tells them they can’t use an American-flagged vessel to do this thing without a permit. Possibly it has something to do with already having signed deals to generate offsets — they’d better throw something in the water or else they’re probably going to have to give the money back.
I have not been able to find anything on verifying the effects of Planktos’s work amid the masses of semi-relevant material on the company website (some of which pops up quite unexpectedly in other languages), aside from something about calculating the effects of a given quantity of iron mathematically and some vague stuff about potentially working with unnamed third parties. If you can find something, let me know.
The moral of the story: if buying carbon offsets has any merit at all, it’s only if you check out the company selling them really, really carefully.