Because unless companies are made to estimate and pay the social costs, or are barred from taking an option that has such a negative impact, we're scuppered. Ad astra per aspera
It would appear that this is exactly the point of court battles raging in the US (at least) over applicability and enforcement of the "Clean Water Act." It seems clear that the US Army Corps of Engineers, under the control of the Bush administration, are testing the limits of the law by granting companies permits that (according to environmentalists bringing suit) permit mining practices that result in violations of the "Act." I can swear there ain't no heaven but I pray there ain't no hell. _ Blood Sweat & Tears