Great idea! I suppose the main incentive would be that it would encourage the chief polluters of the world to curb their excesses and invest in greener forms of energy. When I first read this question, I immediately thought of the way in which those that suffer most from environmental pollution are actually those that are the poorest and most vulnerable individuals in the world anyway. I am thining of, for example, tribes in the Amazon rainforest who have had their way of life destroyed thanks to logging, or the poor in Bangladesh who have found the increased incidence of flooding damaging their already precarious existence. Even though such a law is extremely unlikely to ever be introduced, as there would be massive difficulties in terms of identifying those who had suffered, it would cause developing countries and multi-national businesses to definitely consider their carbon footprint and investigate other greener ways of doing what they do.
In one sense, this is the biggest issue with environmental pollution. There is no tangible cost that comes back straight away at the polluters. Whilst there is of course a cost, it is much more long-term and often impacts others far more than it ever impacts those doing the polluting. Such a law would make polluting hurt for the polluter, which should cause them to think twice about their actions.