Valérie Masson-Delmotte, 47, is a senior scientist from Laboratoire des Sciences du Climat et de l’Environnement, Institut Pierre Simon Laplace. She is the Co-chair of IPCC Working Group I for the AR6 cycle (2015-2022). She has a master and engineering degree from Ecole Centrale Paris in Physics of Fluids and Energetics (1993), a PhD in Past Climate Modelling (1996), and has been a climate scientist at the CEA since 1996. Her research interests include quantifying and understanding past changes in climate and atmospheric water cycle, using analyses from ice cores in Greenland, Antarctica and Tibet, analyses from tree-rings as well as present-day monitoring, and climate modelling for the past and the future. She has worked on issues such as climate variability, climate response to volcanic eruptions and to orbital forcing, polar amplification, climate feedbacks, abrupt climate change and ice sheet vulnerability, climate model evaluation. She is active in outreach for children and for the general public and has co-authored several books on climate change issues. Her research and outreach activity have been recognized by several prizes (European Union Descartes Prize for the EPICA project, 2008; Women scientist Irène Joliot Curie Prize, 2013; Tinker-Muse Prize for science and policy in Antarctica, 2015; Thomson Highly Cited Researcher since 2014; Jean Perrin prize for science outreach from Société Française de Physique, 2018; Nature’s top 10, 2018; CNRS Silver Medal 2019). She was a lead author of IPCC AR4, a coordinating lead author of IPCC AR5 and is co-supervising the preparation of several assessment reports for the IPCC in the AR6 (Global warming of 1.5°C, 2018; Climate change and land, 2019; The ocean and cryosphere in a changing climate, 2019; The physical science basis of climate change 2021).