The Fourth International Conference on Learning Cities, was jointly organized by the UNESCO Institute for Lifelong Learning (UiL) and the Municipality of Medellín; during the 2-day Conference from 1-3 October 2019, there were around 650 conference participants, including 50 mayors, as well as government representatives and experts in the field of education.

This is a bumper edition of the Bulletin in return to school and work month in the northern hemisphere, for the undeniably big reason that we face ecological catastrophe that has led to use of the term Extinction Crisis. It is striking how global warming, something now well- known and established for decades - and long strenuously denied by those with much to lose from the required changes of culture, lifestyle and behaviour – has suddenly burst into life and popular consciousness…