Much the same scenario has occurred to me.
If this scheme works (sequesters large quantities of carbon), it could be worse than anything Goldfinger, Dr. Evil, Lex Luthor, or the Joker could come up with. Taken to extreme (and given the perverse incentives, and whack job characters involved, why wouldn’t it be taken to extreme?) it could trigger a new ice age. For once, the UN got something right. This madness needs to be stopped.
Sorry, but, the UN never gets anything right.