I know the question burning in your mind right now is “How much would I have to pay to own three copies of ABBA’s Definitive Collection all for myself?”. Not just the Greatest Hits or the Mamma Mia soundtrack. No, the one with the word “definitive” in the title. We wouldn’t mind telling you exactly how much it’d cost. But before we do that, we’d like to tell you about a different way to spend the same amount of money. While this option wouldn’t have you rocking out to Swedish 80’s pop songs, it would let you personally prevent a measurable amount of pollution from some of Europe’s biggest greenhouse gas emitters . This eco-sweet opportunity is possible thanks to the European Union Greenhouse Gas Emission Trading Scheme . (Say that five times fast!) The EU ETS, as it’s more easily called, regulates how much greenhouse gas can be emitted by some of the biggest polluters on that side of the pond: coal power plants, oil refineries, coke ovens, cement and paper factories, and the like. Under the Kyoto Protocol, around 11,500 of these European “emissions queens” are required to purchase carbon allowances for all the CO2 they emit. The more carbon allowances are sold the fewer there are on the market and the more expensive they become. With fewer on the market, polluting becomes more costly and companies are forced to find a better way to do business. Still with me? Now we come to the part about the price and the ABBA CD’s. If you were ...