Rifat Unal Sayman has built broad knowledge on various environmental topics, including circular economy, climate change, and sustainable cities through active involvement in more than 50 international and national projects since 2002. He developed sound decision-making and strong leadership skills; as well as profound skills in analysis of key points and numerical information. He developed specific expertise in Regulatory Impact Assessment (RIA) projects and he also have extensively dealt with the transition of the EU Environmental Acquis to Turkey including costs and benefits analysis of the impacts of specific directives to different stakeholders and their local implementation plans. He led several teams to prepare impact assessment studies of WEEE, Packaging Waste, Seveso II, Birds and Habitat Directives, etc. Moreover, he participated at more than 100 national and international conferences, seminars and workshops as speaker or moderator. He took part in the organization of several national and international seminars, conferences and study visits. He is also author or co-author of several reports and articles.