Researchers, intellectuals and spiritual leaders jointly call for swift and just climate action. Together, they formulate the Katowice Memorandum at a symposium co-organized by the Polish Academy of Sciences, the Pontifical Academy of Sciences and the French National Centre for Scientific Research (CNRS) during the 24th UN Conference of the Parties to the UN Framework Convention on Climate Change (COP 24) in Katowice, Poland. The joint symposium has been opened by Jerzy Duszyński, President of the Polish Academy of Sciences, Andrzej Kowalczyk, Rector of the University of Silesia in Katowice, HE Pierre Lévy, French Ambassador to Poland, Stéphanie Thiébault, CNRS Director of Institute of Ecology and Environment, and Msgr Marcello Marcelo Sanchez Sorondo, Chancellor of the Pontifical Academy of Sciences.