The European Union Emissions Trading System was a good idea because it was a free-market and capitalistic solution, as opposed to socialistic solutions the leftist have proposed. We need to save capitalism, because it is now under immense attack from both the environmental constraints and the continuation of automation and roboticization, which many are now saying shows capitalism not to be so good after all.
Yes, the European Union Emissions Trading System was a good idea. It shows that European countries care about the future of this planet and are not stuck in the nationalistic attitudes of countries like America, Russia, and China. By mutually agreeing to control a large amount of emissions, the EU-ETS is guaranteeing a future for all world citizens, not just citizens of the affected countries.