Sennan has a background in environmental science. His research focuses on climate-induced migration and his PhD thesis, submitted in 2019, investigates migration patterns and daily life within informal settlements in Zambia from a climate justice perspective. Sennan co-authored a chapter on climate migration in the Routledge Handbook of Climate Justice. He lectures on migration and environmental issues as part of the MSc Climate Justice programme. He regularly organises workshops and seminars to exchange knowledge about the work of the Centre for Climate Justice.