Pope Francis has opened a highly contentious three-week summit in the Vatican that could potentially clear the way for some married men to become Catholic priests. The meeting -- which focuses on environmental and religious issues in the Amazon region - will take up the question of whether some respected married elder men could be ordained to help overcome a shortage of priests in remote areas in the region. Currently indigenous Catholics in remote parts of the Amazon can go months without seeing a priest or having a proper mass. For more on some of the controversial proposals on the agenda,