Young people perform a flash mob dance during the opening ceremony of the Lisbon European Green Capital 2020 in Lisbon, Portugal, on Jan. 11, 2020. After receiving 2020's European Green Capital Award in June 2018, the Portuguese capital city of Lisbon on Saturday officially launched its transition towards a sustainable future program funded by the award granted by the European Union (EU). (Photo by Pedro Fiuza/Xinhua)