Hélène Van Rossum is Climate Senior Research Fellow, working on climate diplomacy and climate policies, with the aim of increasing climate action and justice. 

Before joining IDDRI, Hélène Van Rossum was a negotiator for the French government at the UNFCCC and the IPCC from 2016 to 2019, contributing to the development of the rules of application for the Global Stocktake, and the adoption of the IPCC report of a warming of 1.5C. More recently, she spent 5 years at the United Nations in New York and Nairobi, working on the implementation of the environmental dimension of the Sustainable Development Goals, in the Executive Office of the Secretary-General and at the United Nations Environment Programme. 

Hélène Van Rossum graduated from a dual Master in Environmental Sciences and Policies from Sciences Po Paris and the Pierre and Marie Curie University in Paris.