Environmental policies are among the priorities of the UN agenda and figure highly in national and international policy agendas. This FEMISE MED BRIEF co-edited with Plan Bleu focuses on two environmental policy instruments – environmental taxes and green public procurement (GPP) – that differ in political viability and in the impact they have on consumers and producers. The document provides a comparative analysis of their efficiency in closed and open economy and reveals the opportunities and threats of (un)harmonised environmental policy across countries. The results allow to consider particular implications for the collaboration of EU-MENA countries.