Duncan is Lecturer in Classical Archaeology at the University of Manchester. His research focuses on the relationship between environment, technology and society in the past, especially in the ancient Mediterranean and in Australia. He is particularly interested in how past and Indigenous practices can help us manage this relationship today. Duncan's research interests are focused on the intersection between Roman society, environment and technology, which he investigates using Latin and Greek texts, archaeological evidence, and geoscientific analyses of limestone deposits.

Duncan has current projects on the climate, flooding and water management in ancient Italy and floodplain management and carbon storage in Australia's channel country, as well as how Roman mortar developed and why it is so durable.  Duncan's long-term research agenda is a holistic, large-scale comparison of key factors – including climatic and environmental variability, population dynamics, land use, disease, instability and governance – influencing Rome's long history, using quantitative estimates (proxies) in a humanities-based interpretative framework. Duncan has previously excavated in Italy, Israel and Australia.