A recent fork from "Where did the G+ Influencers go?" led to discussion of carbon tax. If one understands that greenhouse effect gases like carbon dioxide are increasing due to human activity, and that many economists believe capitalism is the most efficient method humans have thus-far devised to distribute scarce resources, and that governments' functions are partly to regulate market externalities such as environmental impact that do not otherwise have market value; then one might suppose a carbon tax would be a reasonable approach by governments to regulating the carbon dioxide emissions of humanity.
Of course, humanity is served by many different governments. Of course governments are notoriously inefficient in their machinations and often in their use of resources (such as tax income). But externality regulation by means other than taxation has its own problems - permitting may create unanticipated hurdles for some businesses or perpetuate inefficient business arrangements. Arbitrary emission caps may unnecessarily hamper economic growth. Well, many factors may be involved and I am sure others have some ideas about this matter. We should discuss . . .