Walter Block seems to be making a case for something similar to cap and trade here:
That's right; Mr. Libertarian himself agrees with me that there has to be some way to deal with "the commons" (ie, the areas of the environment that cannot be "owned"). Who does he think he is? Fucking communist!!11!!
IMO, this is a good answer from a minarchist perspective. Most libertarians *coughGeorgeReismancough* take the position that corporations have an inherent "right" to pollute and destroy other people's private property.
Good minarchist answer, but how do you apply it in ancapistan?