The EU Emissions Trading System (ETS) has been around for a decade and has seen changes over time. It started with free allowances but now leans towards auctioning them. The system is linked to global climate agreements and EU policies on energy and climate. Researchers analyzed data to see how well the system is working. They looked at emissions, prices for allowances, and the use of offsets to reduce pollution. The findings help understand the current debates on how to improve the EU ETS and other climate policies for the future.