Prof. Toumi was awarded his PhD from the University of Cambridge. In 1994 he moved to the Physics Department at Imperial College. He was promoted to Professor of Atmospheric Physics in 2005 and Head of the Space and Atmospheric Physics Group from 2014-2020.

Since 2020 he is Co-director of the Grantham Institute (Climate Change and Environment) He has co-authored and reviewed many international reports such as WMO Ozone Assessments, SPARC and IPCC Reports. He has served on the ESA mission advisory group and the European Commission Climate Services Road Map group.

He was a founding director of OASIS LMF Ltd which is promoting open access catastrophe modelling for the insurance sector and others. He is advising the Bank of England on physical impacts of climate change on the financial sector. He has published extensively covering a wide range of topics in climate science and currently leads the largest research group on tropical cyclones in Europe.