Teen environmental activist Greta Thunberg on Friday joined protests held in conjunction with a U.N. climate conference in Madrid to urge world leaders to take action on emissions reduction.Tens of thousands of young protestors marched some 4 kilometers in the Spanish capital which is playing host to the 25th session of the Conference of the Parties on climate change, dubbed COP25, to call for effective measures to fight climate change.The 16-year-old Swede, who has become an icon of youth activism, joined the demonstration, and then later spoke to the crowd."We are in the middle of climate…READ FULL ARTICLE