(FILES) In this file photo taken on September 20, 2019, protestors fix a banner on a wall which reads as " Big Climate strike "during the Global Climate strike march in Thies. - Yoro Sarr has learned the hard way: campaigning in Senegal against global warming is not without risk. While trying to mobilize for this cause, an adult broke his jaw and accused him of "opposing the divine will," he said. At 18, the physics and chemistry student from Thies, an hour's drive from Dakar, is the founder of the Senegalese branch of "Fridays for the Future", the global movement launched by Greta Thunberg that brought together several million young people from Sydney to San Francisco, Berlin, Paris and London on September 20. (Photo by SEYLLOU / AFP)