This is why the game is really screwed up. To make these decisions when coming up with carbon credits, or any other decisions regarding resources in a market, policy makers have to defer to industry because they simply don't understand industry and will never have the time to fully understand it like a domain expert would. Now, its not necessarily that the industry's own scientists and experts are corrupt, but that the business models naturally disincentivize hard truths if they come at a cost to profit. Shareholders don't want to hear that their investment is being taxed above others in this case. They will hire lawyers to fight fight fight their battle until its won. There is no opposition here to that, no balance to that sort of reaction, so it continues unimpeded towards this way just as easily and unstoppable as a gunpowder reaction to flame. As such, as soon as you think about putting a restriction on industry, it will serve to benefit investors of that industry first and foremost as it will be penned by that same industry you seek to regulate.