This paper explores how joining the European and Brazilian Emissions Trading Schemes (ETS) can help cut greenhouse gas emissions more affordably. By connecting these separate systems, countries can work together to lower pollution levels. The researchers used economic models to analyze the potential impacts of this partnership. They found that linking these carbon trading systems could make it cheaper for nations to reduce their emissions. Brazil, a leading country in climate change efforts, is considering implementing its ETS. Joining forces with the EU ETS could help Brazil meet its targets and protect the environment.