"Emissions trading or cap and trade is a government-mandated, market-based approach to controlling pollution by providing economic incentives for achieving reductions in the emissions of pollutants."

I repeat: "government-mandated, market-based".

I often sit and wonder if I am liable or not liable -- exempted -- from a breathing tax. I produce carbon dioxide. If I learn to breathe less, then I can sell breaths to you. If I learn to drink less, then I can sell water to you. Or I can plant a forest in the desert, build a well in the earth. Then where, ask the environmentalists, would the snakes and scorpions live?