A Very Bad Preprint With A Very Bad Idea
By This is very badly done. It is hard to know where to start in critiquing it.
The author, Andy Haverly, is said to be at the Rochester Institute of Technology, although another source puts him at Mississippi State University. Haverly “doesn’t have a background in climate science or nuclear engineering,” and his current studies seem to be in computer science.
I guess anything can be published on arxiv. The basic argument of the paper is that climate change is very bad, so it’s hard to see how anything, including an 81-gigaton nuclear explosion, could be worse. There is not much more than that to the argument.
Enhanced rock weathering (ERW) has been an idea since the 1980s. I was present at what may have been the first proposal of ERW. I recognized several problems in that talk, but it was clearly a presentation of a brilliant idea by a brilliant young physicist, so I kept my mouth shut. The problems had to do with that brilliant young physicist’s misunderstanding of mineral formulas and total absence of consideration of thermodynamics. Plus the whole question of scale.
Haverly recognizes the scale problem, which is what leads him to propose a far greater nuclear explosion than has ever been conducted.
Detonating a 81 Gt nuclear device could cause a global catastrophe if done improperly.
He gives no evidence for this, which is the case for most of his important assertions. But yeah, that makes sense. He continues on, waving his hands frantically, to say it won’t be a problem if the device is emplaced in the deep seabed, a few kilometers down.
That 81 Gt is gigatons, a thousand times larger than the 50 megaton ‘Tsar Bomba’ test, the largest nuclear explosion in history, which was 3,800 times the yield of the bomb dropped on Hiroshima. He arrives at 81 Gt by a simplistic calculation of 30 years of carbon dioxide emissions, a volume of basalt that might convert that into carbonate rock, and how much energy it might take to pulverize that volume of basalt.
Explosions, however, are not good at pulverizing rock, and especially not nuclear explosions. I won’t go into all the assumptions, including the very optimistic views of kinetics and diffusion prevalent in ERW. Underground nuclear explosions typically form a chamber with a molten rock wall, which then collapses. The chamber from the Gnome test (1961) did not collapse.
The arrow to the right of center points to a man who has re-entered the chamber. It was un-radioactive enough that he could do that by the standards of the 1960s. Here’s a diagram.
Molten rock is the opposite of the fine powder that ERW advocates need to make their schemes work. It minimizes surface area. Also note that the rocks in the photo are a great deal larger than fine powder.
Then there’s the question of how the seawater would circulate through the shattered rock to contact its surfaces to remove the carbon dioxide in the form of bicarbonate ions. How would seawater from the opposite side of the world reach the explosion site? How would it circulate through the shattered rock? It takes years for the oceans to circulate.
The ecological impact from a nuclear explosion is visible. This nuclear detonation will cause extreme destruction and long term radiation to the detonation site. Choosing a barren seafloor can mitigate the ecosystem destruction, but it will still be uninhabitable for decades. This damage will be contained almost entirely to the dozen square kilometers around the detonation site.
The “long term radiation” would not circulate, but the bicarbonate ions would. I suspect that Haverly does not understand that the radiation comes from ions dissolved in the water in the same way bicarbonate ions are. Either the circulation helps remove bicarbonate AND spreads the radionuclides, or the bicarbonate ions are not removed efficiently and the radionuclides don’t migrate. Again, he has no numbers.
He considers existing treaties relating to nuclear weapons, although he names none of them or their specific prohibitions. And then handwaves them away.
Attempting to detonate the largest nuclear device ever created would certainly affect the delicate situation around nuclear weapons, but these effects can be mitigated. First, it would be clear to everyone that the purpose of this explosion is to sequester carbon. Second, special exceptions to the treaties can be made for such an important problem. Third, open communication would reduce the tensions around this project.
The overall tone of the paper is at a high school level. And I would expect more from a highschooler.
This critique is by no means exhaustive of the errors in the paper.
Many thanks to Brandon Bishop, who discussed the paper on Bluesky and did some sleuthing on the author.
Cross-posted to Nuclear Diner