Thomas Spencer has 15 years’ experience in the fields of energy and climate change policy in Europe, China and India. He was Director of the Energy and Climate Change Program at the Institute for Sustainable Development and International Relations (IDDRI) in Paris, France. He was a member of the French delegation that organised COP21 in 2015, which resulted in the Paris Agreement on Climate Change. Between 2017 and 2021, he was a Fellow at the Energy and Resources Institute (TERI) in New Delhi, India, where his work focused on modelling the expansion and operation of the Indian electricity system under increasing shares of variable renewables. In March 2021, Thomas joined the Energy Modelling Office of the International Energy Agency (IEA). He has been a lead author of numerous IEA publications including the landmark report Net Zero by 2050: A Roadmap for the Global Energy Sector, as well as on several editions of the World Energy Outlook, the agency's flagship annual report.