Dr Velis is an internationally recognised expert in waste and resources management, with a focus on preventing plastic pollution and advancing the circular economy, particularly within the context of a Just Transition in the Global South. In 2024, he joined Imperial College London after over a decade at the University of Leeds, where they led the establishment of the Circular Economy & Resource Recovery (CERRY) network.

He currently chairs the UN Environment-mandated Community of Practice on Harmonisation of Plastic Pollution Quantification Models under the Global Partnership on Marine Litter (GPML), and serves on the CIWM Policy and Innovation Forum. From 2016 to 2022, he led the ISWA Task Force on Marine Litter, contributing substantially to key models and tools such as P2O, WFD, SPOT, and the ISWA Plastic Pollution Calculator, and to the OECD’s Global Plastics Outlook.

Dr Velis is Editor-in-Chief of Waste Management & Research, Specialty Chief Editor for Waste Management at Frontiers in Sustainability, and serves on the editorial boards of Critical Reviews in Environmental Science and Technology and other major journals. His work has been published in Nature, Science, Environmental Science & Technology, and Journal of Hazardous Materials, and is often featured in media including the BBC and The Conversation.

He is a Chartered Waste Manager and active member of several professional bodies, including CIWM and the Institute of Physics and his contributions have extended to global efforts such as the Global Waste Management Outlook and SDG 11.6.1 reporting, supported by his team’s development of the SPOT model.

Dr Velis holds a PhD in Environmental Engineering from Cranfield University, an MSc from Imperial College London, and a BSc in Physics from the University of Athens. He frequently delivers invited lectures and keynotes globally and chairs international scientific sessions.