A picture is projected on the facade and the cupola of St. Peter's Basilica during the show "Fiat Lux : Illuminating Our Common Home," on December 8, 2015 at the Vatican. Images by some of the world's greatest environmental photographers, including Sebasti?o Salgado, Joel Sartore, Yann Arthus-Bertrand and Louie Schwartzberg, are projected in solidarity with COP21 talks in Paris. It is also part of the inauguration of the Roman Catholic Church's yearlong Jubilee of Mercy, which starts today. AFP PHOTO / FILIPPO MONTEFORTE