We see in practice that this sort of damage is extremely difficult to prove, takes years to resolve in court, and is too easily written off as part of the 'cost of doing business' in most cases. In the meantime the damage is still being done to the environment and to the health of the people living in it. In West Virginia, many people affected by the coal industry are dying before they see any resolution in court. If you have acid rain falling on your head, how do you know which of the thousands of factories are responsible? Does everyone affected by the acid rain have to sew every factory operator. In such a system, the only people who win are the lawyers.
What's needed is a system that prevents the damage from being done in the first place. You could certainly argue that court awarded damages could be made high enough to deter bad practices, but that would just encourage frivolous lawsuits and every more acrimony about "environmental activists" undermining profits.
Just to play devil's advocate, if Libertarians really believe the courts could address environmental abuse, why aren't they supporting reforms to the existing court system? It seems to me that every time an issue like this comes up they're almost invariably on the side of pollutersm railing against 'activist judges' and 'environMENTALists.' They give me little hope that such a system would work any better in the great Libertarian utopia.
I'd like to offer an example of responsible environmental protection. I went on a whale watching cruise out of Boston a couple years back and they mentioned that shipping lanes had recently been rerouted to bypass whale feeding areas. Research showed that the whales only gather in certain areas. Rerouting the shipping lanes is yet another case of 'big' government and environmentalists interfering in business, but the fact is that fewer ships hitting whales means less damage to vessels and fewer disruptions to shipping. It's a win-win: safer whales and smoother more effective business operations. This sort of win-win arrangement could never have happened if someone had to go to the courts and try to prove damage. Who's the victim that could even present the lawsuit in this case? Businesses would never make the change on their own - even if the shipping lanes were managed privately - because no company or trade association would ever justify the cost of an "environmental study" to determine the best routes. Maybe they'd do it to pay lip service to good stewardships or as part of a "green" pr campaign, but never because they actually intend to do it properly or take the results seriously.
The fact is that for many years the US had a very Libertarian approach to the environment and many other areas. Regulation and other government interferance only came about because under those laissez-faire policies we had the biggest abuse of the environment the Nation has ever seen. The existing systems have done far better and the question should be how to make them better, not whether or not we should return to an era of policies that clearly didn't work. In some cases, the current system has motivated individual landowners to implement environmental solutions themselves. There was a case a while back of ranchers setting up turtle crossings under roads to keep the government from stepping in and marking the lands as protected. If individuals can solve the problem better than the government - show what they've done and allow independent confirmation of the results - then so much the better for everyone. You can't tell me though that the same results would have been acheived with a glut of lawsuits and fines.