Actually, isn't it a tragedy of the commons? I don't think a carbon tax would adequately address the problem, and it would require a large regulatory apparatus

Actually, isn't it a tragedy of the commons? I don't think a carbon tax would adequately address the problem, and it would require a large regulatory apparatus to enforce it. The oceans and atmosphere get polluted because societies don't have robust enough property rights. Markets are really good at efficiently allocating scarce resources, so we need to figure out how to define strong property rights to allow damaged parties to hold shipping companies liable. As I see it, citizens, companies, and smaller governments (cities, counties, small countries) are powerless to hold large polluters accountable, either because there's not an adequate property-rights based legal framework, or the litigation costs too much.