You probably mean carbon credits, from the EU Emissions Trading System. Wikipedia has a lengthy and well-balanced article on the subject: https://en.wikipedia.o

You probably mean carbon credits, from the EU Emissions Trading System. Wikipedia has a lengthy and well-balanced article on the subject: https://en.wikipedia.org/wiki/European_Union_Emissions_Trading_System https://en.wikipedia.org/wiki/European_Union_Emissions_Tradi... It's an ugly and wasteful system set up instead of other, simpler measure that were politically unacceptable at the time, like higher VAT, excise duties on all fossil fuels across all industries without exception, including fuel oil for heating and aviation fuel.