Marios is a member of the Child & Youth Advisory Board of UNICEF Greece and a strong advocate for climate action and youth participation in decision- and policy making. He has previously served as European Climate Pact Ambassador and been part of youth organizations like Generation Climate Europe and Youth Regional Network. In addition, he has participated in numerous conferences on youth and climate change, including the 9th Our Ocean Conference Youth Leadership Summit. In November 2024, he participated at the COP29 in Azerbaijan, as a youth delegate and part of the Greek delegation. He is currently pursuing his bachelor’s in International and European Studies at the Panteion University of Social and Political Sciences, Athens.