From 1998 until he was elected as the pope, Francis was the Archbishop of Buenos Aires. Throughout his life, both as an individual and a religious leader, he has been known for his humility, his concern for the poor, and his commitment to dialogue as a way to build bridges between people of all backgrounds, beliefs, and faiths. He has expressed concern about the effects of global warming (climate change). In his 2015 encyclical "Laudato si'" , he wrote about these issues, and others.