Kevin Bjornson wrote:
KB) A possible way out of this problem, is to consider pollution that enters property (of someone subscribing to a government with more strict laws against pollution) a form of trespass. Those trespassing in this way could be governed by implied contract, thus binding them to the more strict rules of the victims' government (instead of the polluter's government). (KB
That doesn't matter, as long as the damage the trespass causes is significantly less than the cost to the victim of targeting, contesting, winning, and enforcing a tort claim against the trespasser. This is the fundamental economic concept of non-excludability. For more info, see Can Torts Police All Negative Externalities?
KB) So enforcing rules against pollution do not violate the NAP. (KB
Rules against pollution of non-excludable resources (e.g. atmosphere, oceans, etc.) that are anywhere close to efficient and effective will always result in what someone could call "aggression", because those rules will lump aggressors in with relative non-aggressors. For example, a tax on gasoline corresponding to the average pollution it causes is arguable aggression against those who burn gasoline in the cleanest way possible.
A possible way out of this problem for zero-aggression absolutists is to e.g. make gasoline taxes merely a default, and to allow cleaner burners of gasoline to sue for reduced or eliminated gas taxes. The problem with this, however, is that it still requires the the ZAPsolutist to make the mental and moral leap from 1) designing the rules so as to keep her hands clean, to 2) designing the rules to effectively oppose aggression. Unfortunately, ZAPsolutists would rather see ten thousand micro-aggressors go completely unpunished, than see one innocent falsely accused of micro-aggression and forced to pay a few dollars of unjustified pollution taxes. That's not optimally libertarian.