Ariel is a senior researcher in the Managing Global Governance (MGG) program at the German Institute of Development and Sustainability (IDOS) in Bonn. Since 2021, he has also been a private lecturer at the University of Duisburg-Essen. His research and teaching interests include international negotiations, mediation, stakeholder dialogue, knowledge diplomacy, transformation to sustainability, climate change, climate and environmental justice, sustainability standards and due diligence, international cooperation and development policies of rising powers, sustainable energy, sustainable mobility, game theory, systems analysis, and Global North–Global South cooperation. He holds a habilitation degree from the University of Duisburg-Essen, a PhD in Economics and Social Sciences from the University of Cologne and a PhD in Political Science from the University of Vienna. Ariel has vast experience as a lecturer, curricula designer and researcher in many prestigious institutions across Germany, Mexico, the Philippines, Jamaica, Brazil, Estonia and Spain, has trained hundreds of village leaders in conflict resolution in the Philippines, has hands-on policy experience advising international organizations, government agencies or civil society groups and is an expert in translating research into societal impact.

At THE NEW INSTITUTE, Ariel is involved in the program "Conceptions of Human Flourishing".