I think it's rather that there is another totally reasonable and historically accurate assumption that catastrophic environmental costs need not factor into the projection.
It is not reasonable to assume that because a phenomenon is not observed in a small sample size, that it will also be absent in a much larger sample size. The volume of fracking fluid being pumped into the ground today is orders of magnitude larger than has been used historically.
If our anonymous downvoter has information to the contrary, it would be helpful if they would post it.
I think he means that the companies have a history of not being stuck with environmental cleanup costs or other secondary costs- and thus even if there will be enormous damages, it won't impact their profits.
Ah yes, under that interpretation I would agree wholeheartedly.
Eh, yeah and that's the correct one. In the interests of brevity I guess I left some ambiguity there in what I meant.